The trials logic section provides a rule editor for applying logic to each trial. Rules are built by selecting items from dropdown menus and come in two varieties:
LET
and simply assign values. Generally you would use these rules when defining default values, for example setting correct
to false
in a trial where unless the response is correct (defined by later rules) it is deemed incorrect.IF
and use conditional logic. These rules can be used for defining default values, to determine the correctness of a response or assign levels. For example, (Figure 1) shows some rules for assigning whether or not a response is correct in a lexical decision task. Rule 3 specifies that if level is non-word
and the keyboard key pressed by the participant (response) is the key assigned to pair contains a non-word
then the response is correct. Conversely, if level is non-word
and the keyboard key pressed by the participant (response) is the key assigned to pair only contains real words
then the rule does not match and Rule 1 will remain applied.Rules follow the laws of conditional logic and have the following evaluation properties:
A and B or C
will be evaluated by first resolving (A and B)
and then the result will be applied to the rest of the rule, in this case (ABResult or C)
.correct
will be set to true
, otherwise correct
will remain false
.Click New rule to add a new rule.
Rules can be deleted by selecting the rule using the checkbox and clicking Delete in the toolbar. You can also select and delete multiple rules at once.
The order of rules can be changed by dragging and dropping within the table.