Scaled Scores - Frequently Asked Questions
Our certification exams use scaled scores, which are reported to you in printed form only, in person or by United States mail. The minimum scaled score needed to pass an examination is 75 scaled score units, and the score report will indicate whether you passed or failed. Each candidate handbook has a more detailed explanation of why scaled scores are used, and we suggest you review that information in the handbook if you have questions. The information below is intended to supplement the candidate handbook and answer some of the commonly asked questions. If you need further information or have additional questions, contact us at 412-787-1057 or by email at [email protected]
Why are scaled scores used?
They are used to provide a consistent scale of measurement, so that from one test administration to the next, the same scaled score represents the same level of knowledge.
Why not just use the number of items answered correctly?
This may provide useful information about your performance on different parts of the test but does not take into account the difficulty of the items.
Is a scaled score the same as a percentage score?
No. Calculation of a percent correct is a way to convert a raw score to another scale, but a scaled score is not the same as a percent correct. You could calculate percentage scores by dividing the number correct by the total, for example, a raw score of 9 in a category with 15 total items relates to a 60% correct.
How should I interpret my performance on the category scores?
When reviewing your raw scores for the major categories, bear in mind that all categories are not equally difficult. However, small variations in your subscores probably do not reflect important differences. One more correct answer in a category with 15 items would increase your percent correct score in that category by about seven percentage points.
Why don't I get a percentage score on my report?
Similar to a raw score, converting your score to a percentage score would not take the difficulty of the items into account.
How is the scaled score computed?
To calculate a scaled score, the raw score required to pass is first set equal to 75. An analogous situation is with temperature: 0 degree and 32 degrees both represent freezing on different temperature scales. Raw scores below the passing point are converted in linear fashion to scaled scores below 75; those above the passing point are similarly converted to scaled scores above 75.
Why do I need a 75 to pass the test?
The amount of knowledge required to pass the test is based on the judgments of the content experts who develop the examinations. The raw score required to pass relates to the number of correct answers that a minimally competent (borderline) candidate would be expected to provide, and this raw score is set equal to 75 scaled score units. Different raw scores may be required of different test forms, because all examinations are not equally difficult. The scaled score of 75 required to pass indicates that, while a different number of correct answers may be required from one administration to the next, the passing point for all examinations represents the same level of knowledge.