From LimeSurvey Manual

Dr. Tom White created the Expression Manager (EM) system for LimeSurvey 1.92 and beyond.  EM controls the majority of the survey-taking portion of LimeSurvey, including navigation, conditional branching, validation, and tailoring.

Expression Manager is a partial port of a Java-based survey system (Dialogix) that Dr. White built in 1999 to speed the development and deployment of complex epidemiological assessment and diagnostic instruments.  At present, the main features which still need to be ported include:

  • support for surveys with thousands of questions
  • new database tables and statistics + export tools to store full history of answers (so can see how subjects changed their answers mid-survey)
  • new database tables / statistics / export tools to measure and store response latency
  • export data to SAS
  • have SPSS and SAS exports include automatically generated syntax for
    • descriptive statistics
    • path analysis of user navigation through survey
    • psychometric and usability analysis of the surveys
  • new tables to support item banking and standardization of items using LOINC and SNOMED

More information about Dr. Tom White can be found here:

- Dialogix description:

- LinkedIn profile: