Question type - Equation

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Contents


Short description

Note: This question type became available starting in Version 1.92

This question type lets the author create an equation (e.g. a calculation or tailored report) and save it in a database variable.  Equations can use any syntax supported by Expression Manager. If you are handling numeric values make sure that you use the advanced question setting 'Numbers only' as explained below.

Editing an equation

If you use the HTML editor and need a clean text or a clean numeric value, you need to use HTML source.

Equation seems OK
View source show extra part, not needed. And if numeric is needed : this can break calculation.
We remove all extra HTML, this ensure to have a clean numeric value.

Alternative is to set your preference to use Popup mode if you use a lot of Equation question type


Core settings

Mandatory (mandatory)

Description

This option lets you require that all parts of the question be answered. If you have a question with multiple sub-questions, and want to require that some but not all parts be answered, use the min_answers question attribute instead.

Valid values

  • Yes
  • No (default)



Relevance equation

Notice.png
Hint: This features is available starting in version 1.92


Description

If the value of the relevance equation is "1" or "true", the question is "relevant" in the survey context, i.e. it is shown to the survey participant. If not, the question is hidden. All questions let you specify a relevance equation. Relevance is the successor to conditions and supports much more complex conditional logic.

Syntax Highlighting

Whenever you save the relevance equation, it will be evaluated and syntax-highlighted. Any errors will be color coded so that you can quickly detect and fix them.

Valid values

Any equation, using Expression Manager syntax, without surrounding curly braces.

Examples

Here are good examples of syntax highlighting


Advanced settings

Always hide this question (hidden)

Description

If you prefill a question by URL you can use this setting to hide the question and its value from the survey participant at all. This overrides any conditions because the particular question is never even embedded in a page. If you just want to hide a question (for example if you want to store a value calculated on the fly) then use Javascript embedded in the question source code.

Notice.png
Hint: The question are not diplay in HTML, it can be set with an equation question or survey URL, but not in javascript


Available options

  • On
  • Off (default)


Note: unlike all other question types, if an equation is hidden, it is still computed and its value is still stored in the database.


Numbers only (numbers_only)

Description

If you set this option the participant can only enter numbers in the text boxes.

For equation question types this setting indicates that the result will be a number only, not a string. This will guarantee proper calculations/conversion in follow-up equations regarding the decimal mark.

Behavior by Question-Type

  1. Default: If the subject enters a value that is not a number, that value is immediately cleared from the text box so that the subject can enter an appropriate value.
  2. Array(Texts): Setting this to "No" will overrule "Show totals for" and "Show grand total" setting and total text boxes will not be displayed.
  3. Equation: Setting this option to "Yes" will force equation results to be converted to a numeric value. If the equation result is not a number (and not blank), the equation will return NaN and saved as an empty string in responses table.

Available options

  • Yes
  • No (default)



Insert page break in printable view (page_break)

Description

This attribute is only active when you actually print a survey from the Printable View. It forces a page break before the question. (Only the Opera browser does not need this since it handles the page breaks accordingly.)

Available options

  • Yes
  • No (default)



Show in public statistics (public_statistics)

Description

This attribute allows the admin to chose if the results of a particular question should be shown to the survey participant after he/she has the submitted he survey. Please note that in general to show statistics to the participant the survey setting 'Public statistics' has to be enabled!

The default setting for each question is 'No' (=Do not show statistics of this question to the user). You have to enable this for every single question if you want to show the survey statistics of that particular question to the participant after the survey submission.

Available options

  • Yes
  • No (default)



SPSS export scale type (scale_export)

Description

Used for SPSS export only. This attribute overrides the default scale guessed by SPSS. To learn what the different measurement scales do, please read the related SPSS documentation.

Available options

  • Default (default)
  • Nominal
  • Ordinal
  • Scale