plot method for pairwise DIF statistics
# S3 method for class 'DIF_stats'
plot(x, items = NULL, itemsX = items, itemsY = items, alpha = 0.05, ...)object produced by DIF
character vector of item id's for a subset of the plot. Useful if you have many items. If NULL all items are plotted.
character vector of item id's for the X axis
character vector of item id's for the Y axis
significance level used to color the plot (two sided)
further arguments to plot
Plotting produces an image of the matrix of pairwise DIF statistics. The statistics are standard normal deviates and colored to distinguish significant from non-significant values. If there is no DIF, a proportion alpha off the cells will be colored significant by chance alone.
Feskens, R., Fox, J. P., & Zwitser, R. (2019). Differential item functioning in PISA due to mode effects. In Theoretical and Practical Advances in Computer-based Educational Measurement (pp. 231-247). Springer, Cham.