Identify ILSA files
In ILSAmerge: Merge and Download International Large-Scale Assessments (ILSA) Data

knitr::opts_chunk$set(
  collapse = TRUE
)

library(ILSAmerge)

It is common that ILSA files come an unaggregated format, i.e., separated by country. If that is the case ILSAmerge() is able to identify which files should be merged together.

If we want know how many files were downloaded and into which many files they can be merged, we can use ILSAfile.info() targeting the folder with the unzipped data:

ILSAfile.info(inputdir = system.file("extdata/reds", package = "ILSAmerge"))

As we can see, for 'REDS' 2021 we have 3 file 'types' or populations: BCGV1 (schools), BSGV1 (students), and BTGV1 (teachers). This will become important when we need to work with only one population.