- variable
The label corresponding to the observed variable, for example, "ASDAGE", for the age of the student.
- by
The label for the grouping variable, usually the countries (i.e., by="IDCNTRYL"), but could be any other categorical variable.
- data
An R object, normally a data frame, containing the data from PIRLS.
- export
A logical value. If TRUE, the output is exported to a file in comma-separated value format (.csv) that can be opened from LibreOffice or Excel.
- name
The name of the exported file.
- folder
The folder where the exported file is located.