Because Casper has relatively high test-retest reliability, applicants can expect to score similarly if they are required to take more than one Casper test (e.g., to apply to programs requiring different test types, or to apply to programs in subsequent years). However, in some cases applicants will score in a different quartile from one test to the next. Here are a few possible reasons why this might happen:
Your scores on the two tests were close to the edge of a quartile range (e.g., 74th and 76th percentiles) meaning a small change in score led to being placed in an entirely different quartile.
The caliber of the applicants in the two tests was different, and since Casper is rated and z-scored relative to the strength of your peers’ responses, your demonstrated abilities were more competitive in one test as compared to the other.
You were able to improve your skills between the first and second test, or better demonstrate your skills by being more familiar with the Casper test format (e.g., by taking the practice test in your Acuity Insights account or having been exposed to a real Casper test once before), leading to an improvement in test performance.