Knowledge Base

Variable Scope

The scope of a variable is the portion of the observation for which the variable has a specific value. Choose between the following:

• Observation – A variable has scope Observation if it has the same value during the entire observation. Typical examples of variables with scope Observation are the name of the observer, or the temperature in the observation room. Also, if you observe only one subject per observation, and therefore did not define subjects in your Coding Scheme, variables like Age or Gender of the subject will have scope Observation. The scope of a video or audio file and of external data files is always Observation.
• Event Log – In general there will be no difference between scope Observation and scope Event Log, because each observation contains only one event log. An observation can only have multiple event logs if you imported data as event logs into an observation. This happens, for example, if you import FaceReader facial states into an observation. In this case you can set the scope of a user-defined variable to Event Log if it has different values per event log.
• Subject – This option is only available if you defined Subjects in your coding scheme. If your observation contains multiple subjects and the user-defined variable has different values per subject, select scope Subject. Typical examples of user-defined variables with scope Subject are Age, Gender, and Identity of your subjects.

Notes

• If you plan to create groups of observations for analysis, set the scope to either Observation or Subject, not Event Log. See Create Groups of Data in Select Data for Analysis.
• You can change the scope of a variable at any time. If you do, the variable column shows the first values previously stored for each observation. Enter the variable values according to the new scope.

Value Update

Dependent on your preferences, you are asked to enter Independent Variables before, after, or before and after you carried out an observation. Choose in the Value Update field whether entering variable values is:

• Compulsory – You must enter a value to proceed.
• Manual – If you specified to Hide manual variables in the Project Settings (see Edit Independent Variables), Manual variables are not shown when you are asked to enter the independent variables. Open the independent variable list to update the values.
• Optional – You do not need to enter a value.

To Enter Variable Values

1. Define in the Observation settings (Setup > Project Settings) whether to enter the independent variables before the start of an observation, after the end of an observation, or both.
2. Enter the user-defined variable values in the window that opens when you start or end an observation. It is also possible to enter the values in the independent variables list. You can also copy and paste values from, for example, Excel. However, if you predefined a range, the values should fall within that range.

Manage Independent Variables

Show/Hide Variables

You can select which columns to display in the Independent Variables list.

• To show columns, right-click a column header and select Show Independent Variables.
• To hide one column, right-click in one of the variable fields and choose Hide Independent Variable.

Export Independent Variables

To export the independent variables and their values, choose File > Export > Independent Variables. See Export Independent Variables in File Management.

Edit Predefined Values

To replace or delete predefined values, delete first all the values from the variable column, then delete the values. To remove variables, right-click the column header and choose Delete Independent Variable.

Print the Independent Variables List

In the current version of The Observer XT, printing is not fully supported. To print the independent variable list, copy and paste the columns into another program such as Excel. If you copy the columns to Microsoft Word, you can use the Convert Text to Table function.