Disaggregate and Adjust Value-added Learning Scores

A tool to disaggregate Scantron or ZipGrade pre- and post-test responses into value-added learning scores (Walstad and Wagner 2016) and adjust them for guessing (Smith and Wagner 2017).

What It Does

In the Spring of 2016, Walstad and Wagner released a paper suggesting that the pre-test/post-test delta is insufficient in assessing learning outcomes. A year later, Smith and Wagner showed that this disaggregation should be adjusted using the probability of guessing correct.   However, performing such a disaggregation and adjustment is time intensive, especially if the questions appear in a different location (or order) on the pre- and post-test.


This tool makes disaggregation easy. It uses four CSV (comma separated values) files to generate outcomes by question and student. The first file specifies the mapping between the assessment questions and their locations on the pre- and post-test. The second file is a list of student IDs to use in the assessment. Finally, the last two files are either Scantron files as routinely received from the testing center or ZipGrade formatted exam output files (used the 'standard' export option). The program can also read files from Quick Key with limited modification to the 'quiz itemization report' (the user must remove the header and save the output as a CSV).





Need help?  E-Mail bosmith@unomaha.edu