Skip to main content

Study Rules

Study rules are executable operations defined for a study. They are defined using the studyExpressions language, using similar operations to the survey expression ones but they can also use Action expressions. Action have side effect on the study data (modifying participant state) or trigger action of the system (sending a notification). Concrete examples are given below.

Study rules are the way to define the logic at the study level.

There are 2 ways to use study rules:

  1. By defining them inside the study as internal study rules, they are run each time a study event is triggered like submit when a survey response is submitted or timer when the study timer periodically raise it. The execution of these rules are automatic.

  2. By running a custom rule, using an administration tool, and apply it to all or a subset of participants, this way is useful to run a one shot operation, like manually assign survey or updating flag for some participants (when eligible participants have ben determined externally from the system).

Examples of usage :

  • assign a new survey to a participant, conditionally to the response of another one (create a sequence of surveys)
  • create a report of a participant based on his response
  • trigger a message notification to researcher or to the participant.
  • define a participant flag based on survey response
  • trigger request to an external service (previously registered)

Real life examples​

Assign a survey based on survey response​

The rules will be defined as follow:

  • running on submit event
  • check the survey key is 'profile'
  • if survey response has women for question gender then assign new survey 'womansurvey' to the participant
Only online

Show a question based on another survey's responses​

if you want to have a question shown only for participants with a given condition defined in another survey, you can use a rule creating a flag depending on the survey providing the condition and use the flag in the second survey to trigger the question.

Let's say you want the condition to be women over 50 and you have a first survey named 'profile' asking for age and gender the study rule will be define as follow:

running on submit event check thd survey key is 'profile' if survey response has women for question gender and a value greater than 50 for question age then do, update participant flag women_50 to 1 else update participant flag women_50 to 0

you can now use the flag women_50, in the second survey and trigger the question only if this flag has the value 1 (see survey rules)

Only online