# Important terms in the Trial List

Independent variable

An independent variable is a variable that you define to record specific experiment conditions, the identity of your subjects, or the amount of drug injected.

An independent variable potentially determines the value of a dependent variable, such as speed of movement or distance moved. EthoVision XT assumes that the value of the variable stays constant throughout a trial.

Independent variables are especially useful to create analysis groups.

example The independent variable Treatment with possible values Control, Sham, and Treated. Each subject is assigned one of the values. In the Data profile you can group tracks based on the value of Treatment.

System variable

A system variables is a variable that EthoVision records during acquisition. For example, the duration of a trial, or the name of the video file used in that trial.

Trial

A trial is a single data acquisition session, no matter how many subjects are tracked simultaneously. For each trial, you can enter the value of independent variables.

In the Trial List you can plan your trials. You can add and delete planned trials. You can also delete acquired trials.

See also

▪Analyze groups of tracks