Scaled and Raw Scores
Scaled and Raw Scores
The score report a candidate receives will show the number of items correctly answered in each content area and the whole test. The whole test score is a candidate’s raw score. The report also shows a minimum raw passing score required to pass a test.
A scaled score is NOT a percentage score. A scaled score is simply a transformation of a raw score. Test scores are scaled to report comparable results when test form difficulties vary over time.
The CRNI® exam forms candidates take will change over time. A new form may be slightly more easy or difficult than earlier forms. However, it should not matter to candidates or the certification agency whether candidates take an easier or more difficult form. Easier forms will have proportionately higher raw passing scores and more difficult forms will have proportionately lower raw passing scores. Exact adjustments are derived from candidates’ responses to old and new forms.
When these adjustments in raw passing scores are driven by form difficulties, the effect is to produce an equitable and constant passing standard. Score reports will then express this fact in a scaled passing score that does not change from form to form. The minimum scaled passing score will always have a fixed value like 70 or 75.
Scaled Scores and the CRNI® Score Report FAQ
The information below is intended to supplement the information above and answer some of the commonly asked questions about scaled scores and score reports.
- 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 it does not take into account the difficulty of the items.
- Is a scaled score the same as a percentage score?
No; calculation of a percentage correct is a way to convert a raw score to another scale, but a scaled score is not the same as a percentage 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 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 percentage 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 70. An analogous situation is with temperature: 0° and 32° both represent freezing on different temperature scales. Raw scores below the passing point are converted in linear fashion to scaled scores below 70; those above the passing point are similarly converted to scaled scores above 70.
- Why do I need a 70 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 70 scaled score units. Different raw scores may be required on different test forms, because all examinations are not equally difficult. The scaled score of 70 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.