ARRT to Change Computed Tomography Cut Score on July 1, 2021

On July 1, 2021, ARRT will begin using a new cut score for the Computed Tomography (CT) examination. Although we’ll continue to report the exam’s cut score as a scaled score of 75, the minimum number of correct items necessary to meet this passing threshold will be approximately one more than in the past. The revised cut score reflects new performance expectations for entry-level CT technologists and replaces the previous cut score set in 1995.

Why the Change?

Since 1995, the types of CT exams—as well as the skills and knowledge—needed to perform CT procedures safely have changed. When changes take place, or when it’s been some time since we last evaluated the cut score for an exam, ARRT’s psychometricians conduct a standard-setting study.

In psychometrics, we consider periodic evaluation of cut scores a best practice. Such studies re-evaluate the level of performance necessary to pass an ARRT exam. They give us confidence that cut scores are valid measurements of who should and should not earn ARRT credentials.

What’s a Cut Score?

A cut score is the number of correct answers needed to pass an exam. A passing score shows that a candidate has mastered adequate knowledge to be considered qualified to safely and effectively perform the role being tested.

How Did ARRT Determine the New Cut Score?

To determine an appropriate cut score, our CT Standard Setting Advisory Committee members reviewed each question from a representative version of the exam. Individually, they rated the likelihood that candidates at or just above the passing threshold would answer each question correctly. That process required multiple rounds of ratings and incorporated in-depth discussions with other committee members. The goal was to determine what level of exam performance would demonstrate sufficient knowledge and skills for a candidate to be certified and registered as an entry-level CT technologist.

The advisory committee ultimately submitted its recommendations for the cut score to ARRT’s Board of Trustees. The Board reviewed all information from the standard setting study and the committee recommendation before adopting a revised cut score.

What Effect Will the Change Have?

The standard-setting process helps to ensure that our exam appropriately measures who should and should not become certified and registered in CT. We anticipate that the new cut score and our new performance expectations may lead to a slight decrease in the percentage of candidates who pass the CT exam.