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La posibilidad de condicionar la aparición de una o varias preguntas a la/s respuesta/s que se hayan realizado en preguntas anteriores (ramificación o branching) permite realizar con total fiabilidad encuestas que tienen preguntas interrelacionadas, pues el sistema en línea sólo presentará las preguntas condicionadas cuando efectivamente se cumplan la condiciones impuestas.


Existen de hecho graves inconsistencias cuando las encuestas son rellenadas en formato papel y se tiene este tipo de preguntas, pues en abundantes ocasiones las personas encuestadas no respetan los criterios definidos para contestar o no una pregunta y desafortunadamente estos errores se detectan cuando se van a digitar las respuestas en un sistema, provocando grandes dilemas imposibles de resolver con certeza en ese momento: &iquest;se equivocó al responder una pregunta condicionada? &iquest;se equivocó en la pregunta que era origen de la condición?, y si un cuestionario tiene este problema, &iquest;debe ser descartado por completo?, en caso de no descartarlo, asumiendo desde ese momento pérdida de confianza en los resultados, &iquest;cuál de los errores debe ser enmendado?. Es por lo antedicho que es mucho más recomendable el uso de una plataforma en línea siempre que ésto sea posible, pues garantizará la ausencia de este tipo de errores por parte de los encuestados, lo que brindará mayor confiabilidad en los análisis posteriores.
=Vistazo a las Condiciones en LimeSurvey=


El proceso de condicionamiento o vinculación de una pregunta a otra es muy sencillo y pasamos a describirlo de inmediato:
#Creamos la pregunta que servirá de condición para la aparición/ocultamiento de otras. Para ser fuente de condiciones, sólo serán tomadas en cuenta preguntas de elección (opción única, opción múltiple y matrices).
#Creamos de la forma habitual la pregunta que deseamos esté condicionada a la respuesta de la pregunta anterior. En cualquier momento pulsaremos el botón [[File:icono_ramificacion.png]] de la barra de herramientas de preguntas y al hacerlo se abrirá la siguiente ventana:[[File:formulario_ramificacion.png]]
#En la anterior ventana seleccionaremos una pregunta y, la lista de respuestas se rellenará con las opciones de la pregunta seleccionada, marcaremos las que deseemos (pueden ser varias respuestas al mismo tiempo) y pulsaremos el botón "Agregar condición". Realizaremos este proceso tantas veces como sea necesario, pudiendo borrar cada condición individualmente cuando se necesite.


Es muy importante notar que al marcar varias opciones de la misma pregunta, la decisión de mostrar la pregunta condicionada será disyuntiva (al seleccionar la opción X o bien la opción Y o bien...). Cuando se tienen opciones de diferentes preguntas, la decisión será conjuntiva con las opciones anteriores (al seleccionar la opción X junto con la opción Y...). Veamos un ejemplo de esta característica, mezclando ambas posibilidades en el condicionamiento de una pregunta.
<div class="mw-translate-fuzzy">
LImeSurvey tiene una poderosa forma de configurar la ramificación de una encuesta
</div>


[[File:formulario_ramificacion_ejemplo.png]]
<div class="mw-translate-fuzzy">
En este capítulo, se describirá:
*Qué son las condiciones en LimeSurvey
*Qué puedes y qué no puedes hacer con las condiciones
*Qué pasos necesitas aprender para escribir condiciones simples o complejas
</div>


Como puede apreciarse, se tiene una condición "O" sobre dos de las respuestas de la pregunta 1 y una condición "Y" de una respuesta de la pregunta 2 sobre la disyunción anterior. En el momento presente, éstos son los únicos tipos de condicionamiento disponibles ("O" sobre respuestas de una misma pregunta e "Y" entre respuestas de diferentes preguntas), lo cual afortunadamente cubre la práctica mayoría de casos de condicionamiento.
<div class="mw-translate-fuzzy">
Si quieres ver un video con instrucciones paso a paso, puedes consultar en: http://www.youtube.com/watch?v=oexr0z-eo9U o descargar una encuesta de ejemplo: [[Media:LimeSurvey_sample_survey_Conditions.lss|LimeSurvey_sample_survey_Conditions.lss]].
</div>


A partir de la version 1.92, el flujo de la encuesta (La navegacion y la ramificación) es controlado por el administrador de expresiones (Expression Manager). Todavía puedes usar el Editor de Condiciones que se ha descrito anteriormente. Sin embargo, internamente, EM convierte las condiciones a ecuaciones de relevancia (Relevance Equation). LimeSurvey solo lee la ecuación de relevancia mientras está realizándose la encuesta. De este modo elimina la necesidad de múltiples lecturas a la base de datos, como lo hace el tener una tabla de condiciones.


Sin embargo, no necesitas usar el Editor de Condiciones. Si lo prefieres, puedes configurar ecuaciones de relevancia usando qcode.
{{Hint|Text=The conditions functionalities work like a GUI for [[ExpressionScript - Presentation|the expressions and equations that can be applied to questions]], allowing the users to easily increase the complexity of their surveys without getting into expressions and relevance equations. However, [[ExpressionScript - Presentation|the ExpressionScript]] must be studied/known to increase the range of options that is available within LimeSurvey.}}


Todo lo que puedes hacer con el Editor de Condiciones es compatible con las ecuaciones de relevancia. Sin embargo, EM te da acceso a miles de funciones, y operadores lógicos y matemáticos, que pueden ayudarte a crear complejas ecuaciones de relevancia que nunca podrás hacer con el Editor de Condiciones.


<div class="simplebox">Note:  We currently assume that if you have entered values in the Conditions Editor, you want them to trump anything you manually edit in the Relevance Equation.  If you want to use the Conditions Editor to create the first draft relevance equation and then customize it, you must currently do the following:
==Hide/Show Branching Versus Jump Branching==
#Create your conditions using the Conditions editor as you are used to doing
#Save the conditions - this will show you a syntax-highlighted relevance equation for the question
#Select and copy that syntax-highlighted equation, pasting it into a text editor like NotePad
#Open the Conditions editor again, and delete all conditions for the question (and save) - the relevance equation will disappear
#Edit the question, and paste in the old relevance equation from Notepad, then save the question (or edit the relevance equation further and then save it)</div>


The [[Expression Manager|Expression Manager]] documentation compares/contrasts conditions and relevance, especially [[Expression Manager#How should I choose between Conditions and Relevance?|this table]].


Vistazo las Condiciones en LimeSurvey
Tú puedes diseñar ramificaciones lógicas con LimeSurvey, esto significa que puedes decidir qué preguntas serán mostradas si y solo si algunas condiciones son cumplidas, de la forma "Mostrar Pregunta X si la Pregunta Y tuvo una respuesta Z".


LImeSurvey tiene una poderosa forma de configurar la ramificación de una encuesta
Our approach is to implement a '''Hide/Show Branching Logic''':
* you can define a condition or a set of conditions on each question of your survey - if the condition is met, the question will be then displayed:


En este capítulo, se describirá:
*Qué son las condiciones en LimeSurvey
*Qué puedes y qué no puedes hacer con las condiciones
*Qué pasos necesitas aprender para escribir condiciones simples o complejas


Si quieres ver un video con instrucciones paso a paso, puedes consultar en: http://www.youtube.com/watch?v=oexr0z-eo9U o descargar una encuesta de ejemplo: [[Media:LimeSurvey_sample_survey_Conditions.lss|LimeSurvey_sample_survey_Conditions.lss]].
<center>[[File:simple-condition-on-yes-question.png]]</center>


==Hide/Show Branching Versus Jump Branching==


Tú puedes diseñar ramificaciones lógicas con LimeSurvey, esto significa que puedes decidir qué preguntas serán mostradas si y solo si algunas condiciones son cumplidas, de la froma "Mostrar Pregunta X si la Pregunta Y tuvo una respuesta Z".
<div class='simplebox'> [[File:help.png]] Simply put:
* a question without a condition defined on it will always be displayed;
* a question with a condition defined on it will not be displayed unless the condition is met.</div>


Our approach is to implement a '''Hide/Show Branching Logic''':
This approach is different from the '''Jump Branching Logic''' that is sometimes implemented by other software. In the '''Jump Branching Logic''', the resulting action of a met condition would be to jump to another question (that is to say hide all questions in between). '''LimeSurvey doesn't implement this Jump Branching Logic''' method. Instead, if you wish to jump a series of questions, you should simply set the same condition on all the questions you do not wish to be displayed. For example, if the jump condition you want to set on Question2 is "Jump to Question5 if the answer to Question1 is 'Yes'", you can simply:
* you can define a condition or a set of conditions on each question of your survey: if the condition is met, the question will be displayed
*set a condition on questions 2, 3 and 4 to only display "if the answer to Question1 was '''NOT''' 'Yes'"


Simply put:
LimeSurvey makes setting the same condition on multiple questions (and thus implementing '''Jump Branching Logic''') easy by allowing you to "copy" a condition from one question to a series of others. In the above example, you would begin by setting the condition on Question2, then from the same screen, you would copy that condition to Question3 and Question4.
* a question without a condition defined on it will always be displayed
* a question with a condition defined on it will not be displayed unless the condition is met


This approach is different from the '''Jump Branching Logic''' that is sometimes implemented by other software. In the '''Jump Branching Logic''', the resulting action of a met condition would be to jump to another question (that is to say hide all questions in between). '''LimeSurvey doesn't implement this Jump Branching Logic''' method. Instead if you wish to jump a series of questions, you would simply set the same condition on all the questions you do not wish displayed. For example if the jump condition you want to set on Question2 is "Jump to Question5 if the answer to Question1 is 'Yes'", you can simply:
<div class='simplebox'> [[File:help.png]] To find out more details on how you can copy conditions within LimeSurvey, please continue reading the following [[Setting conditions#How to copy conditions|wiki section]].</div>
*set a condition on questions 2, 3 and 4 to only display "if the answer to Question1 was NOT 'Yes'"


[[File:simple-condition-on-yes-question.png]]
* LimeSurvey makes setting the same condition on multiple questions (and thus implementing '''Jump Branching Logic''') easy by allowing you to "copy" a condition from one question to a series of others. In the above example you would begin by setting the condition on Question2, then from the same screen you would copy that condition to Question3 and Question4.


==Supported Types of Conditions==
==Supported Types of Conditions==


Basically, a condition can compare values and returns true or false.


Values that can be compared are:
Basically, a condition can compare values, returning either true or false.
* '''answers to previous questions'''
 
** for instance: "IF you answered 'Yes' to Question1"
The values that can be compared are '''answers to previous questions'''. For instance, if you answer 'Yes' to Question1, Question2 will then be showed to the survey respondent:
 
 
<center>[[File:Questions_example_set_conditions_y.png]]</center>
 
 
<hr width="50%" style="margin:auto">


[[File:simple-condition-on-F-question.png]]


It is important at this point to understand what is considered as an eligible question-entry for the condition editor:
At this point, it is important to understand what is considered an eligible question-entry for the condition editor.


A ''question-entry'' is either:
A '''question-entry''' is either:
* a simple question (for all question types apart from Array questions)
* a simple question (for all question types apart from Array questions)
** for instance: text questions, radio or dropdown lists, and even multiple choices questions
** for instance: text questions, radio or dropdown lists, and even multiple choices questions
* or a row in Array questions (except for Array dual scale and Array Multiple Flexible questions),
* or a row in Array questions (except for Array dual scale and Array multiple flexible questions)
** for instance: Array of 5 radio buttons, array with label questions
** for instance: array with 5 radio buttons or array with label questions
* or either the left part or the right part of an Array dual scale question
* or either the left part or the right part of an Array dual scale question
* or each cell of an Array Flexible question
* or each cell of an Array flexible question
 
{{Note|Check out the following [[Question types|link]] to find out more about the available question types in LimeSurvey.}}


As a matter of simplification, ''question-entries'' are just called "Question" in this document and the condition editor.
* '''constant values'''
* '''constant values'''
** for instance: "IF you answered more than 3 days to Question2"
** for instance: "If you answered more than 18 years to the question below"
 
 
<center>[[File:simple-condition-on-numerical-question.png]]</center>
 
 
* '''Participants' profile data:''' To use data from the survey participants table, "Anonymized responses" must be set to '''NO'''.  This option can be found in survey [[Participant settings|participant settings]] panel.


[[File:simple-condition-on-numerical-question.png]]
* '''Participant's profile data''' To use '''Token attributes''', "Anonymized responses" must be set to NO.  This option can be found in General Settings -> Tokens tab.


[[File:simple-condition-on-token.png]]
<center>[[File:simple-condition-on-token.png]]</center>


Several comparison operators are supported from the simple "equals", to the advanced "Regular Expression":
 
* The basic ones are equality, and inequality
<hr width="50%" style="margin:auto">
* The greater/less than operator family is also available, and is usually only useful when using numeric question-entries
 
** Please note that comparisons on numeric fields honor the numeric order: for instance 2 < 10
 
** If you're using a question entry whose type is text, then the condition could be evaluated as "2" > "10" (string order)!
Several comparison operators are supported - from the simple "equals" to the advanced "regular expression":
* The basic ones refer to the "equal" and "not equal to" operations
* The ''greater/less than'' operator family is also available, and is usually used when using numeric question-entries
** Please note that comparisons on numeric fields make use of the numeric order. For instance, 2 < 10
** If you're using a question entry whose type is text, the condition could be evaluated as "2" > "10" (string order)!
** Numeric questions, as well as text questions (when they have the 'numbers_only' attribute set), will use the numeric order for comparisons
** Numeric questions, as well as text questions (when they have the 'numbers_only' attribute set), will use the numeric order for comparisons
* An advanced comparison operator using regular expressions is also available.
* An advanced comparison operator using regular expressions is also available (don't panic! If you don't know what this means, then you don't need it)
* The "Regular Expression" operator (don't panic: If you don't know what this means, then you don't need it)
** the pattern is '''not''' to be enclosed in '/' characters
** the pattern is '''not''' to be enclosed in '/' characters
** for instance <div class="simplebox">[a-zA-Z]$
** for instance: '''[a-zA-Z]$'''
 


==How can I combine conditions==
==How can I combine conditions?==


[[File:simple-conditions-combination.png]]


You can '''build complex conditions''' by '''combining simple conditions''' with the '''AND '''and '''OR '''logical operators.
You can '''build complex conditions''' by '''combining simple conditions''' with the '''AND '''and '''OR '''logical operators.


However, it is important to understand that '''LimeSurvey automatically determines which logical operator to apply''': this means that the use of the '''OR '''or '''AND '''operators is determined '''according to the context''' of the condition.


We'll talk about complex conditions later, but let's start by the simple ones first.
<center>[[File:simple-conditions-combination.png]]</center>
 
 
However, it is important to understand that '''LimeSurvey automatically determines which logical operator to apply'''. This means that the use of the '''OR '''or '''AND '''operators is determined '''according to the context''' of the condition. In the above example, there is only one scenario. This means that LimeSurvey makes use of [https://en.wikipedia.org/wiki/Boolean_algebra Boolean algebra], which means that operator '''or''' is "computed" first.
 
We'll talk more about complex conditions [[Setting_conditions#The usage of scenarios - Using ORed conditions between different questions|later]]. Let's first focus together on the elementary ones.
 
=The conditions designer=
 
 
First, you need to access the [[Question toolbar options#The question toolbar|conditions designer]]. To do that, click on the question you wish to apply the condition to:
 
 
<center>[[File:Question designer search question.png]]</center>
 
 
Now, look for the '''Set conditions''' button located on the top question bar:
 
 
<center>[[File:Question designer set conditions.png]]</center>
 
 
Once accessed, the following page will be displayed:
 
 
<center>[[File:Question designer top.png]]</center>
 
 
The conditions designer panel can be divided into three sections:
* [[Setting conditions#The conditions designer toolbar|The conditions designer toolbar]]
* [[Setting conditions#Overview of the existent conditions|The current existent question conditions]]
* [[Setting conditions#Add/Edit conditions|Add/edit condition menu]]
 
 
==The conditions designer toolbar==
 
 
You may find on the toolbar the following options:
 
 
<center>[[File:Show conditions designer toolbar.png]]</center>
 
 
*'''Show conditions for this question''': Click on this button to get a quick overview of the current existent conditions that are applied to your question.
 
*'''Add and edit conditions''': It represents the default page that opens automatically once you click the '''Set conditions''' button. It is divided in two parts: (1) a table displaying all the existent conditions and scenarios, and (2) the [[Setting conditions#Add/Edit conditions|add/edit conditions menu]].
 
*'''Copy conditions''': Sometimes, you wish to apply the same condition to X questions in order to get questionY displayed at the end. For this, click on '''Copy conditions'''. A new window will open displaying the current existent conditions added to your question (let's call it question3). To add them to question5, check the desired conditions you wish to be copied, select question5, and click on the '''Copy conditions''' button located on the bottom left part of the panel. For further information, please continue reading the following [[Setting conditions#How to copy conditions|wiki section]].
 
*'''Save and close''': Once you are done with the changes, click '''Save and close''' to get your conditions saved.
 
*'''Move to question''': In order not to leave the conditions designer panel while moving to another question, use the following option to select from the dropdown list the next question you wish to apply conditions to. Please note that the dropdown list displays the questions that are displayed in the survey before and after the current question.
 
*'''Close''': If you wish to exit the panel without performing any changes, you can either go straight to the settings/structure tab and select the desired option or click '''Close''', which is located in the upper right of the screen.
 
 
==Overview of the existent conditions==
 
 
This section displays a table that contains all the existent scenarios and conditions of a question. Certain actions can be performed from here:
 
 
<center>[[FIle:Show conditions for this questions pic.png]]</center>
 
 
*In the top right part, three actions are available:
**Quick-add conditions - it fastens the process of adding conditions (read [[Setting conditions#Add/Edit conditions|below]] to learn about all the options)
**Renumber scenarios - if clicked, the scenarios will be renumbered with incremental numbers beginning from one. Please note that this option is displayed only if two or more scenarios are applied to your question.
**Delete all conditions - you can delete via this action all the current existent conditions and scenarios applied to your question.
 
 
<center>[[FIle:Conditions designer quickadd and delete.png]]</center>
 
 
*Besides the id number of each scenario there are three buttons that allow you to perform the following actions:
**Delete scenario
**Change scenario number
**Add condition to this scenario - click on this button to add another condition to the desired scenario
 
 
<center>[[FIle:Conditions Designer table scenarios.png]]</center>
 
 
*Two actions can be performed on each condition:
**Delete condition
**Edit condition - if clicked, you will be able to edit the condition from the [[Setting conditions#Add/Edit conditions|conditions menu]]
 
 
<center>[[FIle:Conditions Designer table conditions.png]]</center>
 
==Add/Edit conditions==
 
 
The bottom part of the screen is allocated to the Add/edit conditions menu:
 
 
<center>[[File:Add_edit_condition_q.png]]</center>
 


=Understanding Simple conditions: elementary conditions=
<div class='simplebox'> You can also edit the condition from the same location if you pressed before on the green pencil that corresponds to the question you wish to be edited (see the [[Setting conditions#Overview of the existent conditions|conditions and scenarios table]]).</div>


==Accessing the editor screen==
To understand how the conditions feature works in LimeSurvey, we will first present the elementary conditions.


First you need to access the condition editor:
* open the condition menu by clicking on the ''conditions icon'' in the question button bar, when viewing a question.
* then click on the ''Add and edit conditions icon'', the edit conditions screen will appear allowing you to create, edit or delete conditions for the current question.


The following screen will appear:
<div class='simplebox'>[[File:help.png]] '''Note''': For the moment '''don't modify the default scenario''' ([[File:default_scenario.png]]) that is automatically selected in the condition addition form. It will be covered later within this [[Setting conditions#The usage of scenarios - Using ORed conditions between different questions|wiki section]].</div>


[[File:edit-conditions-EditorView.png]]


Note: for the moment '''don't modify the default scenario''' ([[File:default_scenario.png]]) that is automatically selected in the condition addition form: we'll discuss this later.
===Definition of elementary conditions===


==Definition of elementary conditions==


An elementary condition is simply a single condition '''without any OR or AND''' logical operators.
An elementary condition is simply a single condition '''without any OR or AND''' logical operators.


It is composed by:
It is composed by:
* a left operand: the ''tested value''
* a left operand: the ''tested value''. You can choose the ''tested value'' type by selecting the appropriate tab in the condition editor. It can either be a previous question or a [[Survey participants|survey participant]] attribute.
** you can choose the ''tested value'' type by selecting the appropriate tab in the condition editor
 
 
<center>[[File:edit-conditions-testedvalueTab.png]]</center>
 
 
If you select a question-entry (from the '''Previous questions''' tab) and if this question uses predefined answers, then the corresponding predefined answers are displayed under the '''Predefined''' tab of the comparison value selection.
 
 
<div class='simplebox'> [[File:help.png]] Note that in order to use the Token your survey must:
*not use [[Participant settings|anonymous answers]]
*use a [[Survey participants|survey participants table]] and [[Participant settings|closed access]].</div>
 
 
* a ''comparison operator''. Choose the ''comparison operator'' you want to apply from the dropdown list (''less than'', ''less than or equal to'', ''equals'', ''not equal to'', ''greater than or equal to'', ''greater than'', ''[[ExpressionScript - Presentation|regular expression]]'').
 
 
* a right operand: the ''comparison value''. You can choose the ''comparison value'' type by selecting the appropriate tab in the condition editor. When you create a condition, you can select as the comparison value a predefined value (answer), a constant, a question, a survey participant attribute, or a regular expression:
 


[[File:edit-conditions-testedvalueTab.png]]
<center>[[File:edit-conditions-comparisonvalueTab.png]]</center>
* a ''comparison operator''
** Choose the ''comparison operator'' you want to apply in the dropdown list


[[File:conditions-operators.png]]
===Example of elementary conditions and how to create them===
* a right operand: the ''comparison value''
** you can choose the ''comparison value'' type by selecting the appropriate tab in the condition editor


[[File:edit-conditions-comparisonvalueTab.png]]


==Example of elementary conditions and how to create them==
* Show Question 'AAMN' '''if''' "the answer to Question 'Gender' is the predefined answer 'Male'"
* Show question IF "the answer to Question1 was the predefined answer 'Male'"
** ''tested value'' = answer to Question 'Gender'
** ''tested value'' = answer to Question1
** ''comparison operator'' = equals
** ''comparison operator'' = equals
** ''comparison value'' = answer code of the 'Male' answer
** ''comparison value'' = predefined answer code (the 'Male' answer in this case)
 
 
<center>[[File:edit-simple-condition-predefanswer.png]]</center>
 
 
* Show Question 'Alcohol' '''if''' "the answer to Question 'Age' is greater or equal than the numerical value '18'"
** ''tested value'' = answer to Question 'Age'
** ''comparison operator'' = greater than or equal to
** ''comparison value'' = the constant value '18'
 
 
<center>[[File:edit-simple-condition-constant.png]]</center>
 
 
{{Alert|title=Attention|text=When using a constant 'comparison value' for a date question, regardless of the date format set in your survey, you must use the YYYY-MM-DD date format.}}
 
 
* Show Question 'Alcohol' '''if''' "the answer to Question 'BirthDate' is greater than 2000-01-01'''"
** ''tested value'' = answer to Question 'BirthDate'
** ''comparison operator'' = Greater than or equal to
** ''comparison value'' = '2000-01-01' (the format in the constant field: 2000-01-01)


[[File:edit-simple-condition-predefanswer.png]]
* Show question IF "the answer to Question2 was greater than the numerical value '5'"
** ''tested value''= answer to Question2
** ''comparison operator''= greater than
** ''comparison value''= the constant value 5


[[File:edit-simple-condition-constant.png]]
<center>[[File:Date time example condition.png]]</center>
 
 
* Show Question 'Alcohol' '''if''' "the the 'DrinkingHistory' [[Survey participants|participant's attribute]]" matches the 'Yes' string.
** ''tested value''= the 'DrinkingHistory' value taken from the [[Survey participants#Manage attributes|survey participants table]]
** ''comparison operator'' = equals
** ''comparison value'' = the constant value 'Yes'
 


</div>'''Caution''': When using a constant 'comparison value' for a date question, you must enter the value with the YYY-MM-DD format, whatever the date format is set for current survey.<div class="simplebox">
<center>[[File:edit-simple-condition-leftToken.png]]</center>
* Show question IF "the answer to Question3 was greater than the answer to Question2"
** ''tested value''= answer to Question3
** ''comparison operator''= greater than
** ''comparison value''= answer to Question2


[[File:edit-simple-condition-prevQuestion.png]]
=Conditions and scenarios in LimeSurvey=
* Show question IF "the 'Department' value from the participant's profile (Token Attribute from the invitation) equals the 'Accounting' string"
** ''tested value''= the 'Department' value taken from the token invitation
** ''comparison operator''= equals
** ''comparison value''= the constant value 'Accounting'


[[File:edit-simple-condition-leftToken.png]]


Detailed instructions on how to set up the above example can be found at this blog post: "[http://www.limesurvey-consulting.com/limesurvey-conditions-based-on-token-attributes/ Conditions based on token attributes]"
==Default condition combinations==


=Default condition combinations=


As said earlier, LimeSurvey automatically decides which logical operator (AND or OR) should be applied between conditions depending on the 'context'.
As said earlier, LimeSurvey automatically decides which logical operator (AND or OR) should be applied between conditions depending on the 'context'.
Line 177: Line 293:
Note also that '''the order in which you define your elementary conditions is not relevant''' as LimeSurvey will automatically reorder them according to its own logic.
Note also that '''the order in which you define your elementary conditions is not relevant''' as LimeSurvey will automatically reorder them according to its own logic.


Let's study this in detail.
Let's study this in detail. Two rules should be always remembered:
* [[Setting conditions#First rule: conditions having the same tested value are ORed together|First rule]]: conditions having the same ''tested value'' are ORed together
* [[Setting conditions#Second rule: conditions having different tested value are ANDed together|Second rule]]: conditions having different tested value are ANDed together
 
 
===First rule: conditions having the same ''tested value'' are ORed together===
 
 
When you have several conditions, they are '''ORed''' together if they share the same '''tested value'''. This is the case if the condition applies to several answers belonging to one single question. For example, a condition was applied below to three answers belonging to the same question - if answer to Question 'FavColour' equals 'green' '''OR'''  answer to Question 'FavColour' equals 'red'  '''OR'''  answer to Question 'FavColour' equals 'blue', then Question 'BirthDate' will be displayed to the survey respondent:
 
 
<center>[[File:edit-conditions-naturalOr-edit.png]]
 
[[File:edit-conditions-naturalOr-result.png]]</center>
 
 
<div class='simplebox'>[[File:help.png]] Note: To select multiple predefined answers, don't forget to hold the Shift or Ctrl key while selecting the '''tested values'''.</div>
 
 
===Second rule: conditions having different ''tested value'' are ANDed together===


==First rule: conditions having the same ''tested value'' are ORed together==


When you have several conditions they are '''ORed''' together if they share the same '''tested value'''
When you have several conditions, they are '''ANDed''' together if they don't share the same '''tested values'''. For example, you may see below the case for several conditions based on different previous questions - "If answer to Question 'Alcohol' equals 'Y' answer '''AND''' answer to Question 'Gender' equals 'F'", then Question 'Alcoholconsumption' will be displayed to the survey respondent:
* this is the case for instance for several possible answers of the same previous question: "If answer to Question1 equals 'green' '''OR'''  answer to Question1 equals 'red'  '''OR'''  answer to Question1 equals 'blue'"


[[File:edit-conditions-naturalOr-edit.png]][[File:edit-conditions-naturalOr-result.png]]


==Second rule: conditions having different ''tested value'' are ANDed together==
<center>[[File:edit-conditions-naturalAND-editA.png]]


When you have several conditions, they are '''ANDed''' together if they don't share the same '''tested values'''
[[File:edit-conditions-naturalAND-editB.png]] </center>
* this is the case for instance for several conditions based on different previous questions: "If answer to Question1 equals '4' '''AND''' answer to Question2 equals 'green'"


[[File:edit-conditions-naturalAND-editA.png]]  [[File:edit-conditions-naturalAND-editB.png]]  [[File:edit-conditions-naturalAND-result.png]]
<center>[[File:edit-conditions-naturalAND-result.png]]</center>


==Third rule: ORed elementary conditions take precedence over the other ANDed conditions==


Imagine you define the 3 following sets of conditions:
===The multiple options questions===
*IF answer to Question "Type !" was 'Green'
*IF answer to question "Type 5" was '4'
*IF answer to question "Type A" was '4' or '5'


[[File:edit-conditions-naturalAND-editA.png]][[File:edit-conditions-naturalAND-editB.png]][[File:edit-conditions-naturalANDandOR-editC.png]]
* Then the resulting conditions will be:


[[File:edit-conditions-naturalANDandOR-result.png]]
<div class='simplebox'>[[File:help.png]] '''Note:''' This paragraph applies to ''Multiple options'' and ''Multiple options with comments'' questions, and not to ''Array Multiple Flexible (number) with checkbox layout'' questions (in case of the latter, each checkbox is a separate question-entry and is not really handled as other multiple options question-types).</div>
**Note the '''capital 'OR'''' and the '''lower case 'and'''': this means that ORed conditions are evaluated as if prioritized with parentheses
**Note also that the order of the elementary conditions creation is not preserved and has no importance here
** The resulting conditions is: IF (answer to question "Type A" was '4' '''OR  '''answer to question "Type A" was '4') '''AND '''(IF answer to question "Type 5" was '4') '''AND '''(IF answer to Question "Type !" was 'Green')


==The multiple options questions==


Note: This paragraph applies to ''Multiple options'' and ''Multiple options with comments'' questions, and not to ''Array Multiple Flexible (number) with checkbox layout'' questions (for this later question type, each checkbox is a separate question-entry and is not really handled as other multiple options question-types).
The ''Multiple choice'' and ''Multiple choice with comments'' question types will be displayed in two flavors:
* a ''Group of checkboxes'' flavor which let you set conditions on all possible answers of the respective question;
* a set of ''Single checkbox'' entries which lets you set conditions on each checkbox individually.


[[File:edit-conditions-MultipleOptions1.png]]


For ''Multiple options'' and ''Multiple options with comments'' questions, in the ''tested value''part of the condition editor this question will appear in two flavors
<center>[[File:edit-conditions-MultipleOptions1.png]]</center>
* a ''Group of checkboxes'' flavor which let you set conditions on all possible answers of this question
* a set of ''Single checkbox'' entries which let you set conditions on each checkbox individually


And now let's test your knowledge of conditions by trying to answer this question:
* I've got a multiple options question:
** Issue A: How can I set ORed conditions between different answers of this question
** Issue B: How can I set ANDed conditions between different answers of this question


...
====The group of checkboxes flavour====


...


...
Now, let's focus on an example to better understand the difference between the two flavours. Let's imagine that we wish to display the 'Pointchoice' Question only if the respondent checks at least one of the ''tested answers'' listed under the 'MultipleOrganizations' Question.  


Now the answers...
As mentioned above, the group of checkboxes flavor allows you to set conditions on all possible answers of the respective question. Therefore, only the options that refer to responsibilities are selected as '''comparison values''' below:


For Issue A:
* Use the ''Group of checkboxes'' entry as your ''tested value'' and select as much answers you want


[[File:edit-conditions-MultipleOptionsOR.png]][[File:edit-conditions-MultipleOptionsOR-result.png]]
<center>[[File:edit-conditions-MultipleOptionsOR.png]]</center>


For Issue B:
* Use the ''Single checkbox'' entry that correspond to the first answer you need to set the condition on and set the condition to the ''checked'' ''comparison value''


[[File:edit-conditions-MultipleOptionsAND1.png]]
As we can observe, the conditions get ORed due to the ''Group of checkboxes'' flavour selected in the beginning.:
* Use the ''Single checkbox'' entry that correspond to the second answer you need to set the condition on and set the condition to the ''checked'' ''comparison value''


[[File:edit-conditions-MultipleOptionsAND2.png]]
* Enjoy the result:


[[File:edit-conditions-MultipleOptionsAND-result.png]]
<center>[[File:edit-conditions-MultipleOptionsOR-result.png]]</center>


=Using ORed conditions between different questions: the use of scenario=


Now, you may argue that sometimes you need to have '''ORed''' conditions even when they are set on different questions (that is to say on different '''tested values'''): this is where scenarios can be used.
====ANDing conditions in multiple choice questions====


[[File:multi_scenario.png]]


==Definition of a scenario==
Now, let's focus on a similar example. However, we are looking this time only for the most active members to ask them further questions. To do this, we make use of the '''Single checkbox''' flavour which allows you to set conditions based on each checkbox individually.


A scenario is simply '''a manual grouping of conditions''' in which conditions are evaluated independently of conditions from other scenarios. The complex condition resulting in this association of several scenarios will be met if only one scenario is met: in other words scenarios are '''logical grouping of conditions''', respecting the above rules, and '''which are ORed together''' to build complex conditions.
In this example, question X will be displayed if ''A'' and ''B'' are checked:


All what we described above is true inside a scenario, and by default all new conditions are created inside the "Default Scenario".


However, when you create a new elementary condition, you decide to affect it to another scenario than the default one.
<center>[[File:edit-conditions-MultipleOptionsAND2.png]]</center>


Scenarios are identified by a simple number, the "Default scenario" having number '1' as its identifier.
<center>[[File:edit-conditions-MultipleOptionsAND3.png]]</center>


==Adding a question to another scenario==


When you create (or edit) a condition, you can modify the scenario in which the condition is stored:
Once done, you can observe that the two conditions are ANDed now.


[[File:edit-conditions-EditorView-Scenario.png]]


If you need to define a condition in another scenario than the default one, click the new scenario icon [[File:plus.png]], and type in the scenario number: [[File:default_scenario_edit.png]]
<center>[[File:edit-conditions-MultipleOptionsAND-result.png]]</center>


The number id of a scenario has no importance and different scenarios can have non-continuous ids.


[[File:edit-conditions-EditorView-Scenario2.png]]
This means that your question will not be displayed unless both tested values (the selected subquestions) are met.
 
 
==The usage of scenarios - Using ORed conditions between different questions==
 


=Using the editor=
Now, you may argue that sometimes you need to have '''ORed''' conditions even when they are set on different questions (that is to say on different '''tested values'''). This is why we got scenarios!


==Editor overview==


First you access the condition editor:
===Definition of a scenario===
* open the condition menu by clicking on the ''conditions icon'' in the question button bar, when viewing a question.


The top part of the window always shows any conditions already set for this question:


[[File:existing_conditions.png]]
A scenario is simply '''a manual grouping of conditions''' in which some conditions are evaluated independently of other conditions from other scenarios. The complex condition resulting in this association of several scenarios will be met only if one scenario is met. In other words, scenarios are '''logical grouping of conditions''', respecting the above [[Setting conditions#Default condition combinations|rules]], and '''which are ORed together''' to build complex conditions.


In the example above question B is set to only display if:
Everything described above applies to the conditions located in every scenario. By default, all the new conditions are created inside the ''Default Scenario'', which uses number '1' as its identifier.  When you create new conditions, you can choose whether they are added to the default scenario or not. To change the scenario, just use another identifier.
* The answer to the question-entry FBI of previous question A is "1"
* AND
** EITHER the answer to the question-entry CIA of previous question A is "5"
** OR the answer to the question-entry CIA of previous question A is "3"


In Add/Edit mode [[File:conditions_add.png]], some specific actions are possible on each line such as:
* edit condition [[File:conditions_edit.png]]
* delete all conditions [[File:conditions_deleteall.png]], delete this condition [[File:conditions_delete.png]], delete all conditions from this scenario [[File:scenario_delete.png]]
* edit scenario [[File:scenario_edit.png]]


[[File:edit-conditions-EditModeButtons.png]]
===Adding a question to another scenario===


In Copy mode [[File:conditions_copy.png]], each line is prepended with a checkbox allowing you to select those conditions you want to copy to later questions:


[[File:copying_conditions.png]]
When you create (or edit) a condition, you can modify the scenario in which the condition is stored by simply clicking on the add scenario button:


==Setting new conditions==


===First select the scenario===
<center>[[File:edit-conditions-EditorView-Scenario.png]]</center>


'''If you don't need ORed conditions''' between different question-entries, '''just don't modify the default scenario''' ([[File:default_scenario.png]]) that is automatically selected in the condition edition form.


On the contrary, if you need to define a condition in another scenario than the default one, click the new scenario icon [[File:plus.png]], and type in the scenario number: [[File:default_scenario_edit.png]]
As you can observe, the default scenario uses as identifier '1'. To add conditions to different scenarios, change the identifier by typing a different number in the box.


The number id of a scenario has no importance and different scenarios can have non-continuous ids.
The number id of a scenario has no importance and different scenarios can have non-continuous ids.


===Select the ''tested value''===


Click on the tab corresponding to the type of the ''tested value'' you want: it is either a previous question or a value taken from the profile of the participant (token attribute).
<center>[[File:Conditions test ids.png]]</center>
 
 
You can change the number assigned to a scenario by clicking this Icon [[File:scenario_edit.png]] and assigning the new id to the scenario.
 
 
<center>[[File:edit_scenario_conditions.png]]</center>
 
 
<div class='simplebox'> [[File:help.png]] '''Note:''' As said above, scenario numbers have no impact in the way conditions are evaluated. However, modifying the scenario numbers are needed in order to:
* decide in which order the scenarios are displayed when using the printable version of a survey
* merge conditions from two scenarios (in order to merge scenario 10 with scenario 1, just renumber scenario 10, so that it is scenario 1).</div>
 
 
===Example: creating three scenarios===
 
 
To create three scenarios, you need at least three conditions and to add to each of them a different scenario id. Once done, the scenarios are going to be connected among themselves via the 'OR' operator. For example, it could look like this:
 


Note that '''in order to use the ''Token''''' your survey must:
<center>[[File:edit-conditions-EditorView-Scenario2.png]]</center>
* '''not use anonymous answers'''
* '''use a token table''' and closed access


Then select the entry you want as ''tested value''.
== AND vs OR in the same scenario==


If you select a question-entry (from the 'Previous questions' tab) and if this question uses predefined answers then the corresponding predefined answers are displayed in the ''Predefined'' tab of the ''comparison value'' selection.


===Select the comparison operator===
You may end up in certain cases with AND and OR logical operators in the same scenario:


[[File:comparison_operators_conditions.png]]


Several comparison operators can be used:
<center>[[File:And vs OR example.png]]</center>
* The basic ones are equality, and inequality
* The greater/less than operator family is also available, and is usually only useful when using numeric question-entries
** Please note that comparisons on numeric fields honor the numeric order: for instance 2 < 10
** If you're using a question entry whose type is text, then the condition could be evaluated as "2" > "10" (string order).
** Numeric questions, as well as text questions having the 'numbers_only' attribute set, will use the numeric order for comparisons
* An advanced comparison operator using regular expressions is also available. When selected, the answer input box will automatically switch to the advanced mode.


===Selecting an ''comparison value''===


Select the tab that corresponds to the type of ''comparison value'' you need: it can be a predefined answers, a constant value, an answer from a previous question, a value from a token attribute, or a regular expression (reserved for the advanced regular expression operator).
LimeSurvey will always apply first OR. For further details on this, you may check the following Wikipedia article on [https://en.wikipedia.org/wiki/Boolean_algebra Boolean algebra].


Then select or type in the value you want to use.
However. the order of operations can also be observed in the Relevance equation field. For the above example, the relevance equation is highlighted below:


Note that if you select a value in a tab, then change the tab and select another value in this other tab, the first option you selected is lost.


When using ''predefined answers'', you can then select one or more predefined answers:
<center>[[File:AND vs OR relevance eq.png]]</center>
* the possible answers for that question
** Choose the answer that you want to use
** You can choose multiple answers in one go by using the CTRL button and clicking on more than one answer in the right hand select list


After that click on the "Add Condition" button.


==Editing/Deleting conditions==
As it can be observed, a set of extra parentheses is added for the OR logical operations in order to let the software know that it must be "computed" first.


Apart from adding new conditions, the Add/Edit can be used to
* edit conditions
* delete conditions
* edit scenario


===Edit conditions===
<div class='simplebox'> [[File:help.png]] '''Help:''' For more information on relevance equations, check the [[ExpressionScript - Presentation]] and [[QS:Relevance|relevance equation]] wiki sections. </div>


By clicking on the edit icon [[File:conditions_edit.png]] on a condition line, the edit condition form at the bottom is automatically displayed with the current settings for this condition. Note that in this mode you can only select one predefined answer.
=How to copy conditions=


Click the update condition button to update this condition.


===Delete conditions===
The copy conditions functionality can be used when you wish to apply the same set of conditions you applied to Question5 to Question10. In this way, you will not have to manually recreate the conditions you applied to the previous question(s).


You can:
To start copying conditions, you first have to select the question the condition(s) is/are applied to (Question 'LowQ' in our case). Then, select the conditions you wish to be copied and select the question you wish to have the conditions added to (Question 'Alcohol' in our case).
* delete a single condition by clicking on this icon [[File:conditions_delete.png]]
* delete all conditions within a scenario by clicking on this icon [[File:scenario_delete.png]]
* delete all conditions from this question by clicking on this icon [[File:conditions_deleteall.png]]


===Edit Scenario===


You can change the number assigned to a scenario by clicking this Icon [[File:scenario_edit.png]] and fill-in the form that appears on the same line.
<center>[[File:Copy conditions panel.png]]</center>


[[File:edit_scenario_conditions.png]]


Alternatively, you can renumber scenarios by clicking on this icon [[File:scenario_renumber.png]].
<div class='simplebox'>[[FIle:help.png]] '''Note:''' Conditions can only be set based on questions that appear before the question on which the condition is set.</div>


As said above, scenario numbers have no impact in the way conditions are evaluated. However, modifying the scenario numbers are needed in order to:
Please pay attention to how the copy conditions functions work when you wish to copy and apply a set of conditions located under different scenarios to another question which uses the same or different scenario id numbers. To summarise the possible cases you might have, check the following example:
* decide in which order the scenario are displayed when using the printable version of a survey
* merge conditions from 2 scenarios (in order to merge scenario 10 to scenario 1, just renumber scenario 10 with scenario id 1).


==Copying conditions to later questions==
* you wish to copy Scenario 1 - Condition A, Scenario 1- Condition B, Scenario 7 - Condition C, and Scenario 7 - Condition D from QuestionX into QuestionY
*QuestionY already contains Scenario 1 - Condition A, Scenario - Condition C, Scenario 6 - Condition E, Scenario 8- Condition F.
*Once copied, the following conditions will be applied to QuestionY:
**Scenario 1: Condition A, Condition B, Condition C -> '''Condition A is not copied anymore as it already exists in QuestionY, only condition B being copied.'''
**Scenario 6: Condition E -> not affected
**Scenario 7: Condition C, Condition D -> '''a new scenario is created where the two conditions are added to it'''
**Scenario 8: Condition F -> not affected


It is not uncommon for a group of questions to have the same condition. Luckily you can copy this condition to any subsequent question from the conditions designer once a first condition has been set.


Switch to the copy mode by clicking the on the Copy conditions icon [[File:conditions_copy.png]].
=Reset conditions=


[[File:copy_conditions_example.png]]


The conditions applying to the current questions are displayed with a checkbox on their left. You can:
To quickly reset all the survey conditions, click on one survey-related setting, look for '''Tools''' on the top toolbar, and click '''Reset conditions:'''
* select each condition individually by checking the checkbox on the left of the condition
* or select all conditions from a scenario at a time by checking the checkbox on the left of the scenario


Then select all subsequent questions in the survey on which you want to copy the selected conditions from the bottom Select box by highlighting them (using the CTRL key to select multiples). Then click on the "Copy Conditions" button to copy them across.


It is usually best to leave this until you have finished entering all your survey questions, and are satisfied with the question order.
<center>[[File:Reset_conditions_location.png]]</center>
 
 
Next, confirm on the next page that you want to proceed and all the conditions will be deleted.  
 


=Things to watch out for=
=Things to watch out for=


==General considerations==
==General considerations==


There are a few basic rules you should keep in mind before setting conditions on a question:
There are a few basic rules you should keep in mind before setting conditions on a question:
*Once a single condition has been set for a question, that question '''will not display''' unless that condition is met.
*Once a single condition has been set for a question, that question '''will not be displayed''' unless that condition is met.
*Conditions can only be set based on questions that appear '''before''' the question on which the condition is set.
*Conditions can only be set based on questions that appear '''before''' the question on which the condition is set.
*If you change the order of questions in your survey after you create conditions LimeSurvey does not warn you if the changed order will break a condition. You should always leave the creation of conditions until you are satisifed with the order of questions and groups in your survey.
*If you change the order of questions in your survey after you create conditions, LimeSurvey does not warn you if the changed order will break any of your conditions. You should always put aside the creation of conditions until you are satisfied with the order of questions and groups in your survey.
*You can modify conditions even after a survey has been activated. This should be done with caution, as there is no "consistency checking" applied here.
*You can modify conditions even after a survey has been activated. This should be done with caution, as there is no "consistency checking" applied here.


==Conditions using the 'no answer' predefined answer==
==Conditions using the 'no answer' predefined answer==


[[File:noanswer_conditions.png]]


Setting the following condition "Show question Q20 if answer to question Q1 is 'no answer'" really means "show question Q20 if question Q1 was displayed and received no answer". This is not equivalent to "show question Q20 if question Q1 was not displayed"
<center>[[File:noanswer_conditions.png]]</center>
 
 
Setting the following condition "Show question 'FavColour' if the answer to the question 'Gender' is 'no answer'" really means "show question 'FavColour' if question 'Gender' was displayed to the survey participant who did not submit answer".
 
 
{{Hint|Text=To have the no answer option displayed as a predefined answer, the question cannot be [[QS:Mandatory|mandatory]].}}
 


==Chained conditions==
==Chained conditions==


If you set conditions on a question that, itself, has conditions, then there may arise occasions where the survey behaves in ways you might not have predicted. For example a typical side-effect is that if you hide all questions in a group with chained conditions that the group header will still be shown unless you correct these conditions as explained below.


[[File:chained_conditions1.png]]
If you set conditions on a question that, itself, has conditions, you could end up with your survey behaving in ways you might not have predicted. For example, a typical side-effect is that if you hide all questions in a group with chained conditions, the group header will still be shown unless you correct these conditions as explained below.
 
 
<center>[[File:chained_conditions1.png]]</center>
 
 
<center>[[File:chained_conditions2_bad.png]]</center>
 


[[File:chained_conditions2_bad.png]]
In the above example, the 'Alcohol' question is displayed if the respondent has previously answered to the 'AAMN' question 'No (N)'. However, the 'AAMN' question might not be displayed at the end if the respondent did not select to the previous question ('Gender') answer 'Male (M)'. In this scenario, no 'Alcohol' question will be displayed if 'Male (M)' was chosen previously.


In the example above a question is displayed 'Do you like being male?' which has conditions set, and which will only display if the answer to ''What is your gender?'' is ''M''. If you were to add a condition to this question requiring a specific answer from the ''Do you like being male?'' question, then this question will never display, because the question ''Do you like being male'' will not be presented.
To have the 'Alcohol' question displayed, you have to copy the conditions from the earlier question(s) to the one you're editing. To have the 'Alcohol' question displayed, you need to set up the following set of conditions:
* Show 'AAMN' if the answer to 'Gender' is 'Male (M)'
* Show 'Alcohol' if answer to 'Gender' is 'Male (M)' '''and''' if answer to 'AAMN' is No (N)'.


It is highly recommended that you copy the conditions from the earlier question to the one you're editting.
After correction, the correct set of conditions for 'Alcohol' should look like this:


For instance, you want the following:
* Q1 is a Gender question
* Q2 is a Yes/No and is displayed if answer to Q1 is Male
* Q3 is a ranking question and is displayed if Q2 is Yes


What you really need to setup is the following set of conditions:
<center>[[File:chained_conditions2_good.png]]</center>
* on Q2: display question if answer to Q1 is Male
* on Q3: display question if answer to Q1 is Male AND answer to Q2 is Yes


After correction, the correct set of conditions for Q3 should look like:


[[File:chained_conditions2_good.png]]
So if you are designing a complicated survey with a large number of conditions, make sure you test the survey for as many different combinations of results as you can think of.
 
<div class='simplebox'>[[File:help.png]] To find out more on how you can copy conditions in LimeSurvey, please scroll up or click here to continue reading the dedicates [[Setting_conditions#How_to_copy_conditions|wiki section]].</div>


So if you are designing a complicated survey with large number of conditions, make sure you test the survey for as many different combinations of results as you can think of.


==Limitations and workarounds==
==Limitations and workarounds==


===Progress-bar===
===Progress-bar===


If you create a survey where many questions get skipped because of conditions, the progress bar will jump a big step forward, or the survey ends at 50%.


To avoid such behavior, the questions that could be skipped, should be arranged between the shown questions, so that only one or two questions get skipped per answer.
If you create a survey where many questions get skipped because of conditions, the progress bar either jumps over a set of questions or the survey ends at 50%.
 
To avoid such behavior, the questions that could be skipped should be arranged between the shown questions. In this way, only one or two questions get skipped per answer.
 
For example, based on Question1 (yes or no question), 14 questions (2A to 15A) will be displayed if the answer to Question1 is 'Yes', or 2B to 15B if the answer to Question1 was 'No'.


For Example: based on question one (yes or no question) 14 questions will be asked question 2A to 15A when the answer of question one was yes, 2B to 15B when the answer to question one was no.
If you arrange the questions in one group and arrange them like 2A, 2B, 3A, 3B, and so on, you will get a nearly correct progress bar, while arranging the questions like 2A, 3A, 4A, [...], 2B, 3B, 4B, ... you will get a progress bar from 0 to 50% or from 50% to 100%, depending on the answer to the first question.


If you arrange the questions in one group and arrange them like: 2A, 2B, 3A, 3B, and so on you will get a nearly correct progress bar, while arranging the questions like 2A, 3A, 4A, [...], 2B, 3B, 4B, ... you will get a progress bar from 0 to 50% or from 50% to 100%, depending on the answer to the first question.


=== Setting a constant comparison value for a "Date" Question Type===
=== Setting a constant comparison value for a "Date" Question Type===


You have to use the internal representation of Date values, which is YYYY-MM-DD to define your constant comparison value.
 
You have to use the internal representation of Date values (which is '''YYYY-MM-DD''') to define your constant comparison value.
 


=== Setting conditions for "Other" Options in the Multiple Options Question Type===
=== Setting conditions for "Other" Options in the Multiple Options Question Type===


In the multiple options question type, you can use the "Other" provided in the question type as a valid choice but you cannot set conditions on it. For example: Question No 1 says "Which color do your prefer to use?" Answer checkbox choices are Blue, Black and Other. If the participant chooses Blue, you can set a condition. If the participant chooses Black, you can set a different condition. However, if the participant chooses "Other" and types in something in the text box, there is NO way a condition can be set. LimeSurvey does not recognize if the participant chose the "Other" condition. This is NOT a bug but a limitation.
 
In the multiple options question type, you can use the "Other" provided in the question type as a valid choice but you cannot set conditions on it. For example, Question No 1 says "Which color do you prefer to use?" Answer checkbox choices are Blue, Black and Other. If the participant chooses Blue, you can set a condition. If the participant chooses Black, you can set a different condition. '''However, if the participant chooses "Other" and types in something in the text box, there is NO way a condition can be set.''' LimeSurvey does not recognize if the participant chose the "Other" condition. This is NOT a bug but a limitation.


There is no real field recorded for the 'other' checkbox for this question type. Thus, the only way to know if the user has answered the 'other' part of the question or not would be to check if the value of the text written in the other input field is empty or not.
There is no real field recorded for the 'other' checkbox for this question type. Thus, the only way to know if the user has answered the 'other' part of the question or not would be to check if the value of the text written in the other input field is empty or not.


However, due to the specific way we handle Multiple choice questions, testing the 'other' text input field has never been implemented.
However, due to the specific way Multiple choice questions are handled, testing the 'other' text input field has never been implemented.


As a workaround, add an explicit answer option called 'Other' and do not use the built-in 'other' option of these question types. Then add an additional short text question which will be displayed if this 'Other' checkbox was clicked.
As a workaround, add an explicit answer option called 'Other' and do not use the built-in 'other' option of these question types. Then add an additional short text question which will be displayed if this 'Other' checkbox was clicked.


===How to use parenthesis for the boolean expressions?===
===How to use parenthesis for the boolean expressions?===


'''''You can't!'''''
'''''You can't!'''''
Line 475: Line 579:
If you want to design something like:
If you want to design something like:


 (condition1 OR condition2) AND (condition3 OR condition4)
''(condition1 OR condition2)'' AND ''(condition3 OR condition4)'',


you'll have to set up:
you'll have to set up:


 (condition1 AND condition3) OR
 ''(condition1 AND condition3)'' OR


 (condition1 AND condition4) OR
 ''(condition1 AND condition4)'' OR


 (condition2 AND condition3) OR
 ''(condition2 AND condition3)'' OR


 (condition2 AND condition4)
 ''(condition2 AND condition4)''

Revision as of 19:12, 18 October 2020

Other languages:


Vistazo a las Condiciones en LimeSurvey

LImeSurvey tiene una poderosa forma de configurar la ramificación de una encuesta

En este capítulo, se describirá:

  • Qué son las condiciones en LimeSurvey
  • Qué puedes y qué no puedes hacer con las condiciones
  • Qué pasos necesitas aprender para escribir condiciones simples o complejas

Si quieres ver un video con instrucciones paso a paso, puedes consultar en: http://www.youtube.com/watch?v=oexr0z-eo9U o descargar una encuesta de ejemplo: LimeSurvey_sample_survey_Conditions.lss.


 Hint: The conditions functionalities work like a GUI for the expressions and equations that can be applied to questions, allowing the users to easily increase the complexity of their surveys without getting into expressions and relevance equations. However, the ExpressionScript must be studied/known to increase the range of options that is available within LimeSurvey.


Hide/Show Branching Versus Jump Branching

Tú puedes diseñar ramificaciones lógicas con LimeSurvey, esto significa que puedes decidir qué preguntas serán mostradas si y solo si algunas condiciones son cumplidas, de la forma "Mostrar Pregunta X si la Pregunta Y tuvo una respuesta Z".

Our approach is to implement a Hide/Show Branching Logic:

  • you can define a condition or a set of conditions on each question of your survey - if the condition is met, the question will be then displayed:



Simply put:
  • a question without a condition defined on it will always be displayed;
  • a question with a condition defined on it will not be displayed unless the condition is met.

This approach is different from the Jump Branching Logic that is sometimes implemented by other software. In the Jump Branching Logic, the resulting action of a met condition would be to jump to another question (that is to say hide all questions in between). LimeSurvey doesn't implement this Jump Branching Logic method. Instead, if you wish to jump a series of questions, you should simply set the same condition on all the questions you do not wish to be displayed. For example, if the jump condition you want to set on Question2 is "Jump to Question5 if the answer to Question1 is 'Yes'", you can simply:

  • set a condition on questions 2, 3 and 4 to only display "if the answer to Question1 was NOT 'Yes'"

LimeSurvey makes setting the same condition on multiple questions (and thus implementing Jump Branching Logic) easy by allowing you to "copy" a condition from one question to a series of others. In the above example, you would begin by setting the condition on Question2, then from the same screen, you would copy that condition to Question3 and Question4.

To find out more details on how you can copy conditions within LimeSurvey, please continue reading the following wiki section.


Supported Types of Conditions

Basically, a condition can compare values, returning either true or false.

The values that can be compared are answers to previous questions. For instance, if you answer 'Yes' to Question1, Question2 will then be showed to the survey respondent:




At this point, it is important to understand what is considered an eligible question-entry for the condition editor.

A question-entry is either:

  • a simple question (for all question types apart from Array questions)
    • for instance: text questions, radio or dropdown lists, and even multiple choices questions
  • or a row in Array questions (except for Array dual scale and Array multiple flexible questions)
    • for instance: array with 5 radio buttons or array with label questions
  • or either the left part or the right part of an Array dual scale question
  • or each cell of an Array flexible question
Check out the following link to find out more about the available question types in LimeSurvey.
  • constant values
    • for instance: "If you answered more than 18 years to the question below"



  • Participants' profile data: To use data from the survey participants table, "Anonymized responses" must be set to NO.  This option can be found in survey participant settings panel.




Several comparison operators are supported - from the simple "equals" to the advanced "regular expression":

  • The basic ones refer to the "equal" and "not equal to" operations
  • The greater/less than operator family is also available, and is usually used when using numeric question-entries
    • Please note that comparisons on numeric fields make use of the numeric order. For instance, 2 < 10
    • If you're using a question entry whose type is text, the condition could be evaluated as "2" > "10" (string order)!
    • Numeric questions, as well as text questions (when they have the 'numbers_only' attribute set), will use the numeric order for comparisons
  • An advanced comparison operator using regular expressions is also available (don't panic! If you don't know what this means, then you don't need it)
    • the pattern is not to be enclosed in '/' characters
    • for instance: [a-zA-Z]$


How can I combine conditions?

You can build complex conditions by combining simple conditions with the AND and OR logical operators.



However, it is important to understand that LimeSurvey automatically determines which logical operator to apply. This means that the use of the OR or AND operators is determined according to the context of the condition. In the above example, there is only one scenario. This means that LimeSurvey makes use of Boolean algebra, which means that operator or is "computed" first.

We'll talk more about complex conditions later. Let's first focus together on the elementary ones.

The conditions designer

First, you need to access the conditions designer. To do that, click on the question you wish to apply the condition to:



Now, look for the Set conditions button located on the top question bar:



Once accessed, the following page will be displayed:



The conditions designer panel can be divided into three sections:


The conditions designer toolbar

You may find on the toolbar the following options:



  • Show conditions for this question: Click on this button to get a quick overview of the current existent conditions that are applied to your question.
  • Add and edit conditions: It represents the default page that opens automatically once you click the Set conditions button. It is divided in two parts: (1) a table displaying all the existent conditions and scenarios, and (2) the add/edit conditions menu.
  • Copy conditions: Sometimes, you wish to apply the same condition to X questions in order to get questionY displayed at the end. For this, click on Copy conditions. A new window will open displaying the current existent conditions added to your question (let's call it question3). To add them to question5, check the desired conditions you wish to be copied, select question5, and click on the Copy conditions button located on the bottom left part of the panel. For further information, please continue reading the following wiki section.
  • Save and close: Once you are done with the changes, click Save and close to get your conditions saved.
  • Move to question: In order not to leave the conditions designer panel while moving to another question, use the following option to select from the dropdown list the next question you wish to apply conditions to. Please note that the dropdown list displays the questions that are displayed in the survey before and after the current question.
  • Close: If you wish to exit the panel without performing any changes, you can either go straight to the settings/structure tab and select the desired option or click Close, which is located in the upper right of the screen.


Overview of the existent conditions

This section displays a table that contains all the existent scenarios and conditions of a question. Certain actions can be performed from here:



  • In the top right part, three actions are available:
    • Quick-add conditions - it fastens the process of adding conditions (read below to learn about all the options)
    • Renumber scenarios - if clicked, the scenarios will be renumbered with incremental numbers beginning from one. Please note that this option is displayed only if two or more scenarios are applied to your question.
    • Delete all conditions - you can delete via this action all the current existent conditions and scenarios applied to your question.



  • Besides the id number of each scenario there are three buttons that allow you to perform the following actions:
    • Delete scenario
    • Change scenario number
    • Add condition to this scenario - click on this button to add another condition to the desired scenario



  • Two actions can be performed on each condition:
    • Delete condition
    • Edit condition - if clicked, you will be able to edit the condition from the conditions menu


Add/Edit conditions

The bottom part of the screen is allocated to the Add/edit conditions menu:



You can also edit the condition from the same location if you pressed before on the green pencil that corresponds to the question you wish to be edited (see the conditions and scenarios table).

To understand how the conditions feature works in LimeSurvey, we will first present the elementary conditions.


Note: For the moment don't modify the default scenario () that is automatically selected in the condition addition form. It will be covered later within this wiki section.


Definition of elementary conditions

An elementary condition is simply a single condition without any OR or AND logical operators.

It is composed by:

  • a left operand: the tested value. You can choose the tested value type by selecting the appropriate tab in the condition editor. It can either be a previous question or a survey participant attribute.



If you select a question-entry (from the Previous questions tab) and if this question uses predefined answers, then the corresponding predefined answers are displayed under the Predefined tab of the comparison value selection.


Note that in order to use the Token your survey must:


  • a comparison operator. Choose the comparison operator you want to apply from the dropdown list (less than, less than or equal to, equals, not equal to, greater than or equal to, greater than, regular expression).


  • a right operand: the comparison value. You can choose the comparison value type by selecting the appropriate tab in the condition editor. When you create a condition, you can select as the comparison value a predefined value (answer), a constant, a question, a survey participant attribute, or a regular expression:


Example of elementary conditions and how to create them

  • Show Question 'AAMN' if "the answer to Question 'Gender' is the predefined answer 'Male'"
    • tested value = answer to Question 'Gender'
    • comparison operator = equals
    • comparison value = predefined answer code (the 'Male' answer in this case)



  • Show Question 'Alcohol' if "the answer to Question 'Age' is greater or equal than the numerical value '18'"
    • tested value = answer to Question 'Age'
    • comparison operator = greater than or equal to
    • comparison value = the constant value '18'



  Attention : When using a constant 'comparison value' for a date question, regardless of the date format set in your survey, you must use the YYYY-MM-DD date format.



  • Show Question 'Alcohol' if "the answer to Question 'BirthDate' is greater than 2000-01-01"
    • tested value = answer to Question 'BirthDate'
    • comparison operator = Greater than or equal to
    • comparison value = '2000-01-01' (the format in the constant field: 2000-01-01)



  • Show Question 'Alcohol' if "the the 'DrinkingHistory' participant's attribute" matches the 'Yes' string.
    • tested value= the 'DrinkingHistory' value taken from the survey participants table
    • comparison operator = equals
    • comparison value = the constant value 'Yes'


Conditions and scenarios in LimeSurvey

Default condition combinations

As said earlier, LimeSurvey automatically decides which logical operator (AND or OR) should be applied between conditions depending on the 'context'.

Note also that the order in which you define your elementary conditions is not relevant as LimeSurvey will automatically reorder them according to its own logic.

Let's study this in detail. Two rules should be always remembered:

  • First rule: conditions having the same tested value are ORed together
  • Second rule: conditions having different tested value are ANDed together


First rule: conditions having the same tested value are ORed together

When you have several conditions, they are ORed together if they share the same tested value. This is the case if the condition applies to several answers belonging to one single question. For example, a condition was applied below to three answers belonging to the same question - if answer to Question 'FavColour' equals 'green' OR  answer to Question 'FavColour' equals 'red'  OR  answer to Question 'FavColour' equals 'blue', then Question 'BirthDate' will be displayed to the survey respondent:



Note: To select multiple predefined answers, don't forget to hold the Shift or Ctrl key while selecting the tested values.


Second rule: conditions having different tested value are ANDed together

When you have several conditions, they are ANDed together if they don't share the same tested values. For example, you may see below the case for several conditions based on different previous questions - "If answer to Question 'Alcohol' equals 'Y' answer AND answer to Question 'Gender' equals 'F'", then Question 'Alcoholconsumption' will be displayed to the survey respondent:



The multiple options questions

Note: This paragraph applies to Multiple options and Multiple options with comments questions, and not to Array Multiple Flexible (number) with checkbox layout questions (in case of the latter, each checkbox is a separate question-entry and is not really handled as other multiple options question-types).


The Multiple choice and Multiple choice with comments question types will be displayed in two flavors:

  • a Group of checkboxes flavor which let you set conditions on all possible answers of the respective question;
  • a set of Single checkbox entries which lets you set conditions on each checkbox individually.



The group of checkboxes flavour

Now, let's focus on an example to better understand the difference between the two flavours. Let's imagine that we wish to display the 'Pointchoice' Question only if the respondent checks at least one of the tested answers listed under the 'MultipleOrganizations' Question.

As mentioned above, the group of checkboxes flavor allows you to set conditions on all possible answers of the respective question. Therefore, only the options that refer to responsibilities are selected as comparison values below:



As we can observe, the conditions get ORed due to the Group of checkboxes flavour selected in the beginning.:



ANDing conditions in multiple choice questions

Now, let's focus on a similar example. However, we are looking this time only for the most active members to ask them further questions. To do this, we make use of the Single checkbox flavour which allows you to set conditions based on each checkbox individually.

In this example, question X will be displayed if A and B are checked:



Once done, you can observe that the two conditions are ANDed now.



This means that your question will not be displayed unless both tested values (the selected subquestions) are met.


The usage of scenarios - Using ORed conditions between different questions

Now, you may argue that sometimes you need to have ORed conditions even when they are set on different questions (that is to say on different tested values). This is why we got scenarios!


Definition of a scenario

A scenario is simply a manual grouping of conditions in which some conditions are evaluated independently of other conditions from other scenarios. The complex condition resulting in this association of several scenarios will be met only if one scenario is met. In other words, scenarios are logical grouping of conditions, respecting the above rules, and which are ORed together to build complex conditions.

Everything described above applies to the conditions located in every scenario. By default, all the new conditions are created inside the Default Scenario, which uses number '1' as its identifier. When you create new conditions, you can choose whether they are added to the default scenario or not. To change the scenario, just use another identifier.


Adding a question to another scenario

When you create (or edit) a condition, you can modify the scenario in which the condition is stored by simply clicking on the add scenario button:



As you can observe, the default scenario uses as identifier '1'. To add conditions to different scenarios, change the identifier by typing a different number in the box.

The number id of a scenario has no importance and different scenarios can have non-continuous ids.



You can change the number assigned to a scenario by clicking this Icon and assigning the new id to the scenario.



Note: As said above, scenario numbers have no impact in the way conditions are evaluated. However, modifying the scenario numbers are needed in order to:
  • decide in which order the scenarios are displayed when using the printable version of a survey
  • merge conditions from two scenarios (in order to merge scenario 10 with scenario 1, just renumber scenario 10, so that it is scenario 1).


Example: creating three scenarios

To create three scenarios, you need at least three conditions and to add to each of them a different scenario id. Once done, the scenarios are going to be connected among themselves via the 'OR' operator. For example, it could look like this:


AND vs OR in the same scenario

You may end up in certain cases with AND and OR logical operators in the same scenario:



LimeSurvey will always apply first OR. For further details on this, you may check the following Wikipedia article on Boolean algebra.

However. the order of operations can also be observed in the Relevance equation field. For the above example, the relevance equation is highlighted below:



As it can be observed, a set of extra parentheses is added for the OR logical operations in order to let the software know that it must be "computed" first.


Help: For more information on relevance equations, check the ExpressionScript - Presentation and relevance equation wiki sections.

How to copy conditions

The copy conditions functionality can be used when you wish to apply the same set of conditions you applied to Question5 to Question10. In this way, you will not have to manually recreate the conditions you applied to the previous question(s).

To start copying conditions, you first have to select the question the condition(s) is/are applied to (Question 'LowQ' in our case). Then, select the conditions you wish to be copied and select the question you wish to have the conditions added to (Question 'Alcohol' in our case).



Note: Conditions can only be set based on questions that appear before the question on which the condition is set.

Please pay attention to how the copy conditions functions work when you wish to copy and apply a set of conditions located under different scenarios to another question which uses the same or different scenario id numbers. To summarise the possible cases you might have, check the following example:

  • you wish to copy Scenario 1 - Condition A, Scenario 1- Condition B, Scenario 7 - Condition C, and Scenario 7 - Condition D from QuestionX into QuestionY
  • QuestionY already contains Scenario 1 - Condition A, Scenario - Condition C, Scenario 6 - Condition E, Scenario 8- Condition F.
  • Once copied, the following conditions will be applied to QuestionY:
    • Scenario 1: Condition A, Condition B, Condition C -> Condition A is not copied anymore as it already exists in QuestionY, only condition B being copied.
    • Scenario 6: Condition E -> not affected
    • Scenario 7: Condition C, Condition D -> a new scenario is created where the two conditions are added to it
    • Scenario 8: Condition F -> not affected


Reset conditions

To quickly reset all the survey conditions, click on one survey-related setting, look for Tools on the top toolbar, and click Reset conditions:



Next, confirm on the next page that you want to proceed and all the conditions will be deleted.


Things to watch out for

General considerations

There are a few basic rules you should keep in mind before setting conditions on a question:

  • Once a single condition has been set for a question, that question will not be displayed unless that condition is met.
  • Conditions can only be set based on questions that appear before the question on which the condition is set.
  • If you change the order of questions in your survey after you create conditions, LimeSurvey does not warn you if the changed order will break any of your conditions. You should always put aside the creation of conditions until you are satisfied with the order of questions and groups in your survey.
  • You can modify conditions even after a survey has been activated. This should be done with caution, as there is no "consistency checking" applied here.


Conditions using the 'no answer' predefined answer


Setting the following condition "Show question 'FavColour' if the answer to the question 'Gender' is 'no answer'" really means "show question 'FavColour' if question 'Gender' was displayed to the survey participant who did not submit answer".


 Hint: To have the no answer option displayed as a predefined answer, the question cannot be mandatory.


Chained conditions

If you set conditions on a question that, itself, has conditions, you could end up with your survey behaving in ways you might not have predicted. For example, a typical side-effect is that if you hide all questions in a group with chained conditions, the group header will still be shown unless you correct these conditions as explained below.




In the above example, the 'Alcohol' question is displayed if the respondent has previously answered to the 'AAMN' question 'No (N)'. However, the 'AAMN' question might not be displayed at the end if the respondent did not select to the previous question ('Gender') answer 'Male (M)'. In this scenario, no 'Alcohol' question will be displayed if 'Male (M)' was chosen previously.

To have the 'Alcohol' question displayed, you have to copy the conditions from the earlier question(s) to the one you're editing. To have the 'Alcohol' question displayed, you need to set up the following set of conditions:

  • Show 'AAMN' if the answer to 'Gender' is 'Male (M)'
  • Show 'Alcohol' if answer to 'Gender' is 'Male (M)' and if answer to 'AAMN' is No (N)'.

After correction, the correct set of conditions for 'Alcohol' should look like this:



So if you are designing a complicated survey with a large number of conditions, make sure you test the survey for as many different combinations of results as you can think of.

To find out more on how you can copy conditions in LimeSurvey, please scroll up or click here to continue reading the dedicates wiki section.


Limitations and workarounds

Progress-bar

If you create a survey where many questions get skipped because of conditions, the progress bar either jumps over a set of questions or the survey ends at 50%.

To avoid such behavior, the questions that could be skipped should be arranged between the shown questions. In this way, only one or two questions get skipped per answer.

For example, based on Question1 (yes or no question), 14 questions (2A to 15A) will be displayed if the answer to Question1 is 'Yes', or 2B to 15B if the answer to Question1 was 'No'.

If you arrange the questions in one group and arrange them like 2A, 2B, 3A, 3B, and so on, you will get a nearly correct progress bar, while arranging the questions like 2A, 3A, 4A, [...], 2B, 3B, 4B, ... you will get a progress bar from 0 to 50% or from 50% to 100%, depending on the answer to the first question.


Setting a constant comparison value for a "Date" Question Type

You have to use the internal representation of Date values (which is YYYY-MM-DD) to define your constant comparison value.


Setting conditions for "Other" Options in the Multiple Options Question Type

In the multiple options question type, you can use the "Other" provided in the question type as a valid choice but you cannot set conditions on it. For example, Question No 1 says "Which color do you prefer to use?" Answer checkbox choices are Blue, Black and Other. If the participant chooses Blue, you can set a condition. If the participant chooses Black, you can set a different condition. However, if the participant chooses "Other" and types in something in the text box, there is NO way a condition can be set. LimeSurvey does not recognize if the participant chose the "Other" condition. This is NOT a bug but a limitation.

There is no real field recorded for the 'other' checkbox for this question type. Thus, the only way to know if the user has answered the 'other' part of the question or not would be to check if the value of the text written in the other input field is empty or not.

However, due to the specific way Multiple choice questions are handled, testing the 'other' text input field has never been implemented.

As a workaround, add an explicit answer option called 'Other' and do not use the built-in 'other' option of these question types. Then add an additional short text question which will be displayed if this 'Other' checkbox was clicked.


How to use parenthesis for the boolean expressions?

You can't!

If you want to design something like:

(condition1 OR condition2) AND (condition3 OR condition4),

you'll have to set up:

 (condition1 AND condition3) OR

 (condition1 AND condition4) OR

 (condition2 AND condition3) OR

 (condition2 AND condition4)

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