Main Article Content
This paper introduces intsvy, an R package for working with international assessment data (e.g., PISA, TIMSS, PIRLS). The package includes functions for importing data, performing data analysis, and visualizing results. The paper describes the underlying methodology and provides real data examples. Tools for importing data allow useRs to select variables from student, home, school, and teacher survey instruments as well as for specific countries. Data analysis functions take into account the complex sample design (with replicate weights) and rotated test forms (with plausible values of achievement scores) in the calculation of point estimates and standard errors of means, standard deviations, regression coefficients, correlation coefficients, and frequency tables. Visualization tools present data aggregates in standardized graphical form.