CHES® Exam Background and Scoring

The CHES® examination contains 165 items; 150 of the items are scored and 15 of the items are used as pilot items and do not contribute to the final score on each exam. Examinees are informed that there are pilot items on the exam, however, the candidate is not told which items are being piloted and which items are being scored. NCHEC pilots new items on the CHES® exam to ensure high statistical integrity of this certification examination. Item piloting is used to determine the psychometric properties of an item before the item is actually included as a “scored item” on an examination. This also allows for the removal of items that do not perform at acceptable levels for certifying examinations.

Determining the Passing Point on the CHES® Exam

NCHEC has used the Modified Angoff method and variations of this method to set the passing point for the CHES® examination. The Modified Angoff method is the most widely used criterion-referenced passing point technique within the credentialing industry and is based on the judgment of content experts regarding the expected test performance of candidates who are just qualified. This criterion-referenced procedure sets the performance standard before the examination is taken by candidates. Therefore, this standard is independent of examinee performance. Essentially, this method allows subject-matter experts to establish a consistent level of knowledge that is expected of professionals who are just qualified for certification. There is also no penalty for guessing on an item on the exam. The results are reviewed by NCHEC and a final standard is set. This standard is upheld on every subsequent form of the CHES® examination using a statistical process called equating. Although all examination forms are based on the same test blueprint and are carefully constructed to have similar difficulty levels, slight differences in difficulty are unavoidable. To ensure that candidates who take an easier or more difficult form of the examination do not have an advantage or disadvantage, equating is used to adjust the passing point for the difficulty level of the form.

Reliability and Validity of the CHES® Exam

Item analyses are conducted and the results are reviewed for each examination form administered. Reliability of the examination is calculated using the Kuder-Richardson Formula 20 (KR20). Reliability coefficients above 0.80 are considered satisfactory for credentialing exams. The CHES® exam reliability coefficient, as determined by the KR20, has consistently met or exceeded the standard over the years.

Confidentiality Policy

The exam score is confidential and will not be disclosed unless NCHEC receives a written request to do so from a candidate or is directed to do so by subpoena or court order. A candidate wanting scores released to another entity must indicate in writing which particular scores may be disclosed and identify specifically the person or organization to which the scores should be revealed. No candidate scores will be given by telephone, facsimile or e-mail for any reason.

Statistical Information Regading the CHES® April 2016 and October 2016 Examinations