Task Parameters

The Task Parameters section contains details about your task. An example looks like this:

[Task Parameters]
experiment_code_version = 1.0
num_conds = 1
num_counters = 1

experiment_code_version [ string ]

Often you might run a couple different versions of an experiment during a research project (e.g., Experiment 1 and 2 of a paper). experiment_code_version is a string which is written into the database along with your data helping you remember which version of the code each participant was given.

This variable is used by the server along with num_conds and num_counters to ensure an equal number of workers per condition for the current experiment_code_version. In other words, changing the experiment_code_version resets the number of workers per condition to [0 0].

num_conds [ integer ]

psiTurk includes a primitive system for counterbalancing participants to conditions. If you specify a number of condition greater than 1, then psiTurk will attempt to assign new participants to conditions to keep them all with equal N. It also takes into account the time delay between a person being assigned to a condition and completing a condition (or possibly withdrawing). Thus, you can be fairly assured that after running 100 subjects in two conditions each condition will have 50+/- completed participants.


If you want to reset the random assignment when changing num_conds, update the experiment_code_version.

num_counters [ integer ]

num_counters is identical to num_cond but provides an additional counterbalancing factor beyond condition. If num_counters is greater than 1 then psiTurk behaves as if there are num_cond*num_counters conditions and assigns subjects randomly to the the expanded design. See Issue #53 for more info.