# Free interval based on multiple subjects

Procedure

When working with multiple subjects per arena, you can define free intervals in two ways:

▪Under Nesting, choose Free interval to define a Free interval for each subject separately. The interval is based on the behavior of that subject, not the other(s).

As a result, for each subject a specific time period is selected.

▪Under Nesting over Subjects, choose Free interval to define an interval based on a combination of conditions based on two or more subjects. The resulting interval is applied to all subjects.

As a result, the same time period is selected for all subjects.

Example

Your arena contains two subjects. A free interval is defined that goes from Total Distance moved >= 100 to Total Distance moved >=200.

▪If you choose Free interval from Nesting, the start/stop criteria are applied per subject, resulting in most cases in different time periods being analyzed for each subject.

Below: Time plot of a dependent variable (in this example, Distance moved) after defining the Free interval from Nesting. Different time periods are analyzed for Subject 1 (from A1 to B1) and Subject 2 (from A2 to B2).

▪If you choose Free Interval from Nesting over Subjects, the start/stop criteria are applied per subject, but the interval are defined after combining the criteria based on what is selected in the Actors tab.

Below: Time plots of a dependent variable (in this example distance moved) after defining a Free interval from Nesting over Subjects (compare with the previous figure). Depending on what is selected in the Actors tab:

▪With All selected subjects (top). The time period shared between subjects (from A1 to B2).

▪With Any selected subject (middle). The time period defined by at least one subject (from A2 to B1).

▪With one subject selected (bottom). The time period defined by the criterion met by that subject (in this example, subject 2; therefore, from A2 to B2).