Prometric, the US-based testing company organising the computer-based Common Admission Test (CAT) has finally cleared the air on how it would bring uniformity in the difficulty levels of various sets of question papers.
Since CAT became an online test from 2009, the test is being held
over a number of days and it requires different sets of question papers on the same subject. This triggered questions as to how Prometric was equating the scores.
With a month left for the next CAT exam, Prometric has come up with an explanation. The first step is to calculate the raw score.
The raw score is derived by giving three points for each correct answer and subtracting one point for each incorrect answer. This helps ensure that candidates are rewarded for what they know and not for random guessing.
The second step is where the difficulty factor of various question sets is taken into account.
"If two candidates take different versions of the paper and get the same number of answers correct, it would not be fair to consider them equally capable unless we could prove that each form was equally challenging. So, the second step of the process involves equating the forms," said a Prometric spokesperson.
The spokesperson said, "A small number of questions are present in more than one version of the paper. These questions allow us to measure how candidates taking different forms compare against each other when asked the same question. By using enough of these questions across all forms, we can adjust each candidate's raw score and provide each candidate with the scores they would have earned had each candidate taken the exact same form, at the same time."
The process is completed by placing the equated scores on a common scale. Scaling creates a range of scores, which can be used to create a percentile rank for the test as a whole, and for each section. Candidates scoring in the top percentile performed at the highest level.
Prometric will release some online videos to familiarise candidates with the process.