ChooseUsingCheckbox. The interview will represent this command as a Checkbox. The values of the data element thus chosen will be ‘true’ or an empty string. For example:
<<When(PersonIsMale = “true”,he,she)>>

The command is quite customizable, so another variation could be:
<<When(Sex = “M”,he,she)>>

In this case the second ‘F’ indicates that the initial state (before a user clicks in it) of the checkbox is the unchecked state, and its value is the value when unchecked, viz. ‘F’.

Where this default value is not specified (as in <<ChooseUsingCheckBox(AttendSchool,Yes,No)>>) or is specified but is neither the value when checked nor the value when unchecked (e.g.<<ChooseUsingCheckBox(AttendSchool,Yes,No,Don't Know)>>)) then the checkbox is first shown in the indeterminate state – i.e. neither checked nor unchecked.