Understanding Scaled Scoring in Certification Examinations
In the world of certification exams, ensuring fairness and consistency is vital. One effective method to achieve these objectives is through scaled scoring, which transforms raw test scores into a standardized scale, facilitating equitable comparisons across different test forms and administrations. Below, we will delve into the concept of scaled scoring, its implementation, and its advantages.
What Are Raw Scores?
To understand scaled scoring, it is important to have basic knowledge of raw scores. A raw score represents the total number of test items a candidate answers correctly. For example, in a 100-item test, if a candidate answers 70 questions correctly, their raw score is 70. Traditionally, a specific raw score, such as 70, might be set as the passing threshold. However, this approach can present challenges, especially when multiple test forms or varying test lengths are involved.
Challenges with Raw Scores
When multiple forms of a test exist, even with efforts to maintain equivalent difficulty levels, slight variations are inevitable. Consequently, different forms might require different raw cut scores to account for these variations. For instance, Form A might have a cut score of 70, while the slightly easier Form B might have a cut score of 71. This discrepancy can lead to confusion among candidates, especially if two individuals achieve the same raw score on different forms but receive different pass/fail outcomes.
Additionally, for organizations offering multiple credentials with tests of varying lengths (e.g., 80, 100, or 150 items), reporting raw scores can result in multiple score scales and cut scores, further complicating score interpretation for candidates and stakeholders.
What Is Scaled Scoring?
A scaled score is a score that has been transformed from a raw score (i.e., the number of correct answers) to a standardized scale. This transformation is similar to converting from Celsius to Fahrenheit. The temperature has not changed, only the degrees reported have. Scaled scores indicate the same level of performance, regardless of which exam form a test taker has received.
Scaled scores are used to allow for direct comparisons of exam scores. Any differences in exam difficulty are accounted for using scaled scores. With different exam forms being developed on a regular basis, differences in the difficulty of individual exam questions can result in variances in the difficulty of an exam form. When there are variations in the difficulty of exam forms, the same raw score may represent different levels of knowledge or competency. For example, a higher raw score on an easier exam form may represent the same knowledge or competency as a lower score on a more difficult exam form.
How Are Scaled Scores Set?
To establish scaled scores, testing programs often employ standard setting methods, such as the Angoff Method. This approach involves Subject Matter Experts (SMEs) evaluating each test item to determine the percentage of minimally competent practitioners who would answer it correctly. These evaluations inform the determination of the cut score—the minimum score required to pass the exam.
In addition, to address differences in exam forms, SMEs use a process known as “equating”, which applies the same passing standard to exam forms that vary in difficulty.
Equating is a statistical procedure that adjusts the cut score to reflect differences in form difficulty, thus maintaining an equivalent passing standard. Equating ensures that:
- Test takers who take an easier form are not given an unfair advantage, and
- Test takers who take a more difficult form are not penalized.
These evaluations inform the minimum score required to pass the exam.
Benefits of Scaled Scoring
- Simplified Score Interpretation: Candidates and stakeholders can more easily understand and interpret scores when a consistent scale and cut score are used across all test forms.
- Fairness Across Test Forms: Scaled scoring accounts for minor variations in test form difficulty, ensuring that all candidates are held to the same standard, regardless of the specific form they encounter.
- Consistency Across Multiple Credentials: For organizations offering various credentials with tests of differing lengths, scaled scoring provides a unified score scale and cut score, reducing potential confusion.
- Enhanced Communication: A standardized scoring scale facilitates clearer communication of results to candidates and other stakeholders, minimizing misunderstandings.
Conclusion
Scaled scoring is a fundamental practice in certification testing, promoting fairness, consistency, and clarity in score reporting. By converting raw scores to a standardized scale, testing programs can ensure that all candidates are evaluated equitably, regardless of the specific test form or credentialing exam they undertake. This approach not only simplifies score interpretation but also upholds the integrity of the certification process.
For more information on scaled scoring, check out PSI’s article on the subject.
