ORSEE3

The third part of your experiment's main page provides statistics on the various participation states with respect to your experiment. (Participation states can be defined/customized in Options/Participation states, see Participation states.)

The eligibility of subjects to participate in your experiment is defined by assigning participants to the experiment. To do this, choose Assign Subjects from the options part. You will see a (more or less human-readable) form to construct a query into the database. The query tool is very flexible, and allows you define any possible (combination of) eligibility conditions. The default is to select all subjects not yet assigned to your experiment. You adding further conditions by moving your mouse over “Add condition” and selecting a condition type (which we call “query modules” in ORSEE).

To find the right set of conditions, just try to formulate an intact sentence by choosing its different parts from this menu (e.g.. “Select all … where gender is 'female' … and where field of studies is 'economics' … and without subjects who have participated at one of the following experiments: 'Dictator Game','Ultimatum Game' … , but maximally 100 subjects”).

In the current version, the following query modules are implemented in ORSEE:

• Profile text fields search: freetext search in any textline and textarea participant profile form field (if enabled for the respective field, see section Participant profile form), as well as in internal fields (participant_id, participant_id_crypt, remarks);
• No-show count: condition on the number of no-shows, this is the essential statistic used in the reputation system;
• Participation count: condition on the number of previous experiment participations;
• Participant activity: condition on the time a participant last enrolled in a session (“Last session enrolment”), updated her profile form data (“Last participant profile update”), registered for the database (“profile creation date”), or the closest of any of these dates (“Last activity”);
• Sub-subjectpool: condition on the sub-subjectpool of participants;
• Interface language: when you offer the ORSEE page in different language, you can condition here on the language the participant has chosen for their interface;
• Profile field: for any select_lang, radioline_lang,select_text, radioline participant profile form field, you can condition on one or more values in this field;
• Profile field: for any select_numbers participant profile form field, you can compare the value in this field to a number of your choice;
• Prior participation - Experiment classes: condition on the type(s) of experiments the subject has participated in before;
• Prior participation - Experimenter: condition on in which researcher's experiments the subject has participated in before;
• Prior participation - Experiments: condition on particular experiments the subject has participated in before;
• Assigned to experiments: condition on particular experiments the subject is currently eligible for.

Any condition can be expressed as an exclusion (the subjects matching the criterium should not be eligible) or inclusion (only subjects matching the criterium will be eligible). The conditions can be combined by AND or OR logical operators, and brackets can be used to structure the query (Add brackets).

The handles at the left of each condition row can be used to move conditions within the query. To ensure validity of the query, the movement of brackets is restricted. The (upper) opening bracket can be used to move the bracket (including its content) within the query. The (lower) closing bracket allows to extend the bracket to include more conditions. Conditions can also be moved directly into the query and out. The query parser will ignore empty bracket pairs.

In addition to the conditions, you can choose Limited to a random subset to restrict the result set to a randomly selected sample that match your criteria. The small delete buttons on the right of each condition allow you to remove a condition from the query.

There are two more buttons on the top of the form. One allows you to reset the query form. With the other you can load a previously used query (that resulted in the assignment of a non-zero number of participants) onto the form. The default query loaded onto the query form of an experiment before the first assignment can be set in Options/Default and saved queries.)

After you made your selection, click on Search and Show. You will receive a list of all participants satisfying your query. (The columns in this results list can be configured in Options/Query result lists.) You can assign all of the subjects in the result set to your experiment by clicking on theAssign all participants in list button, or assign only a subset of the listed participants by selecting them and clicking the button Assign only selected participants. After submitting, you will receive feedback about how many participants were assigned, and the page will return to the query form. Whenever this procedure leads to the assignment of a non-zero number of participants, the query is saved to the database, and will also be included in the ORSEE recruitment report for your experiment.

After completing your participant assignments you can see the total number of assigned participants in the participants section in the bottom part of your experiment's main page.