VisualDF Home

VisualDF version 2.0.4

VisualDF was created to provide a free, open-source program with an intuitive Excel interface to compute effect size indices of differential functioning of items and tests/scales.

Download Now


  • Support for 1-3PL and GRM Models
  • Prompt-driven set-up
  • Open-source Visual Basic for Applications code
  • Produces easily customizable graphs in Excel


Note: VisualDF is now baked into the MIRT package in R. This software is no longer actively maintained.  Please see my guide to invariance testing using R instead.


Citing VisualDF:  Meade, A. W. (2010). A taxonomy of differential functioning effect size indices. Journal of Applied Psychology95, 728-743.