The trials logic section provides a rule editor for applying logic to each trial.
Rules strictly follow the laws of logic and have the following evaluation properties:
- left to right: for example,
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).
- rule precedence: All rules are sequentially evaluated for each trial in the order they appear in the rules table with later rules taking precedence over earlier rules. For example, after the rules in (Figure 1) are evaluated, the result will be
level = Congruent as the latter rule takes precedence over any former rule.
response constructs such as keyboard response
and buttons response
also have their own events. These events are not affected by trials rules.
Figure 1. Rule precedence example
Adding a rule
Click New rule to add a new rule.
Deleting a 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.