Rasch model analysis has the following set of advantages
- Being logit scores, Rasch scores have no theoretical upper and lower boundary values (useful for statistical analysis)
- Rasch scores facilitate pretest and posttest comparison based on different set of test items (You can avoid taking identical test at pre and post)
- Rasch model can handle missing values (as long as a subject is not missing all items)
- Rasch model (or Rasch model software programs) comes with an excellent set of diagnostics statistics to evaluate the model and data fit