Knowledge Base

Trial List

Introduction to the Trial List

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 variable 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.

Useful Things to Know About the Trial List

To Open the Trial List: Choose Setup > Trial List, or in the Experiment Explorer click Trial List.

To Show and Hide Variables in the Trial List:

1. Do one of the following:
   • Click the Show/Hide button on the toolbar and select Variables.
   • Right-click a column header and choose Show Variable.
2. In the Show Variables window, select the variables of your choice and click Apply.

Tip: Under System, also choose Subject Not Found and Missed Samples. These two variables give useful information about the reliability of your data.

To Sort Columns in the Trial List: You can change the order of the columns. Click the column header to select the column of your choice and then drag it to the new position. While you drag it, a red line shows the insertion point of the column.

To Show and Hide Row Headers in the Trial List: Do one of the following:

• Click the Show/Hide button on the toolbar, select Row Headers, and then select the headers you want to display.
• Right-click on any of the headers (Trial, Arena, Subject, No.) and select which headers you want to display.

Import External Data Button: If you have the External Data Module, the Import External Data button is available on the toolbar of the Trial List. Click this button to import external data like EEG or Heart Rate into EthoVision XT and synchronize it with the tracks.

Independent Variables

Define an Independent Variable

To label trials, arenas and subjects using an independent variable, for example the level of the treatment, the ID of the subjects and the day of testing:

1. Open the Trial List.
2. Click the Add Variable button. A new column with the label User-Defined is inserted at the end of the table.
3. Specify the label (name), description, type, format, predefined values and scope of the variable.

Delete an Independent Variable

To remove an independent variable that you no longer need in your experiment. This action removes the column from the Trial List and also removes the values of the variable assigned to each trial, arena and subject.

Right-click the column header and choose Delete Variable.

Notes:

• You can only delete variables that you defined yourself.
• To hide system variables, see System Variables.

Variable Values, Formats and Other Properties

Variable Label: In the Label field enter the name of the variable. The name must be unique. Names cannot be longer than 64 characters. The characters you use must be Unicode characters in the Basic Multilingual Plane range.

Variable Description: In the Description field you can enter a short text or any other background information about the variable. The description is limited to 255 characters. The characters you use must be Unicode characters in the Basic Multilingual Plane range.

Variable Type: Click the Type field and from the drop-down list choose one of the following options:

• Text: A text variable is denoted by alphanumeric characters, composed of letters, numbers or both. For example, the name of the treatment.
• Numerical: A variable represented by numbers only, for example, the dose of the drug that you apply.
• Time Stamp: A variable represented by a time stamp, for example, the start date and time of the trial.
• Duration: A variable represented by a duration, for example the duration of the treatment.
• Boolean: A variable that is either False or True. For example, the presence of a novel object in the arena.

Variable Format:

• For Text variables you do not need to specify a format.
• For Numerical variables, double-click in the Format field. In the Format window, select No. of Decimals and enter the number of decimals (1 to 9). If you work with integer values, leave the check box unselected. Select Scientific Notation if you want to write, for example, 1485 as 1.485e+0.03. In the Unit field, enter the unit of your variable, for instance µg/g for the dose of the drug, then click OK. To enter Greek symbols, use the Windows Character Map.
• For Time Stamp variables, click in the Format field. In the Format String window, enter your preferred format in the field at the top.
• For Duration variables, click in the Format field. In the Format String window, enter your preferred format in the field at the top.
• For Boolean variables you do not need to specify a format.

Predefined Values:

• For Text variables, double-click in the Predefined Values field. In the Predefined Values window, under Predefined Value enter one of the possible values of the independent variable, then click Add. Repeat this step for all values. Keep the Allow Other Values check box selected if you are not sure whether the values that you defined are exhaustive. Clear this option if the values under Predefined Values are exhaustive. To delete a predefined value, select it in the Predefined Values field and click Remove. The characters you use must be Unicode characters in the Basic Multilingual Plane range.
  Example: Your independent variable is the treatment you apply, with possible values drug and saline. Enter drug, then click Add. Repeat this step for saline.
• For Numerical variables, double-click in the Predefined Values field. In the Predefine Numerical Values window, select one of the following options:
  • Allow Any Value: Select this option if you do not want to predefine a range of values or individual values.
  • Define a Range: Define a minimum and maximum value. For instance, when the age of the rats in your experiment ranges from 6 to 18 months, enter 6 as the minimum value and 18 as the maximum.
  • Define Individual Values: Select this option when you are, for instance, testing a drug in three dosages: 0.05, 0.1 and 0.5 mg/g. Enter 0.05 in the Predefined Value field and click Add. The value moves to the Predefined Values field. Repeat this procedure for the other two values. Keep the Allow Other Values check box selected if you are not sure whether the values that you defined are exhaustive. Clear the check box if you are sure that you do not want to add new independent variable values. To delete a predefined value, select it in the Predefined Values field and click Remove.
• For Time Stamp and Duration variables you cannot specify any predefined values.
• For Boolean variables, double-click in the Predefined Values field. In the Predefine Boolean window, enter values for True and False. For instance, if your independent variable is Presence of Novel Object, define the values Yes (True) and No (False).

Variable Scope: For the scope of an independent variable you can choose between the following three options: Trial, Arena and Subject.

Example: The scope of the variable Bedding Type is Trial if all the arenas in a trial have the same kind of bedding material. Select Arena if the bedding material differs for different arenas during the same trial. For variables whose values may differ between subjects in the same arena and trial, select Subject. For instance, in two-subject interaction tests, the variable Sex (with subject 1 being male, and subject 2 female) or Status (subject 1 being resident, and subject 2 intruder).

System Variables

To View or Hide a System Variable:

1. From the Show/Hide menu on the toolbar, choose Variables.
2. Select the variables you want to view. To hide a system variable, clear its check box.

Acquisition Status: The current status per arena:

• Planned: When a trial is added to the Trial List, all the arenas within the trial get the status Planned.
• To Skip: You can give an arena the status To Skip when for any reason you do not want or cannot track a subject in that arena. For example, when the subject that was planned in that arena is no longer available.
• Skipped: The status Skipped is given to an arena that was previously set to To Skip. The status Skipped is therefore a label given after the trial has been acquired (or at least video was recorded for that trial).
• Postponed: This label appears when you choose to record video and track later. After recording video, the arenas within a trial get the status Postponed. After you do tracking from that video, the status changes to Acquired.
• Postponed to Skip: If you have recorded video without tracking, the status of the trials and arenas in the Trial List is Postponed. You can then choose to skip one of the trials or arenas by selecting Postponed to Skip. Do this for example if one of the arenas in the video is empty.