Basically, a useful, valid and reliable test is one that covers a specific portion of material such that it would be unlikely that an examinee would do well on one part of the exam, and poorly on another part.
Item analysis describes the statistical analyses which allow measurement of the effectiveness of individual test items. Item analysis is a procedure that is used to improve the validity and reliability of multiple-choice tests. The statistical results imply that the current National Board of Forensic Evaluators (NBFE) examination can well predict a candidate's knowledge of essential forensic constructs. Each judge estimated what score they would receive on the exam based on their expertise, and their scores on other forensic measures. A measure of predictive ability associated with the current National Board of Forensic Evaluators (NBFE) and the Hoffman Institute's examination was achieved by having 16 forensic SME's take the exam.
The forensic SME's concluded that the items that comprise the current version of the National Board of Forensic Evaluators (NBFE) and the Hoffman Institute's examination for NBFE certification correlate strongly with other measures of forensic expertise.Īccording to predictive validity, a valid exam must be strongly correlated with another (valid) measure such that one can make a valid prediction by simply knowing the score on only one of the measures. These forensic SME's carefully reviewed the content of the exam, question by question, to determine if the questions tested the same domains (constructs) as other forensic measures do. The current National Board of Forensic Evaluators (NBFE) and the Hoffman Institute's examination for NBFE certification utilized the input of 16 forensic subject matter experts (SME's) (e.g., forensic practitioners) who served as judges and exam evaluators. The result of this is an increase in the exam's content validity and utility when used as a certification tool.Īccording to concurrent validity, a test or exam is valid to the extent that it varies directly with a measure of the same construct, or indirectly with a measure of an opposite construct. The exam was constructed to measure a candidate's knowledge across a broad spectrum of current forensic practice. The current National Board of Forensic Evaluators (NBFE) and the Hoffman Institute's examination for NBFE certification measures knowledge representative of 20 forensic domains (constructs). Essentially, the term validity is global in that it is comprised of 3 validity sub-types content validity, concurrent validity, and predictive validity.Īccording to content validity, a test or exam is valid to the extent that it represents all of the content of a particular construct. Validity refers to the degree to which an exam truly measures what it is intended to measure.
These statistical measures and procedures used, and the results, are summarized below. In order to determine the applicability of this exam to serve as a certification tool for forensic experts, rigorous statistical testing for examination validity, item analysis, variability, and cutoff score determination was completed. The forensic domains that are tested include the following: The National Board of Forensic Evaluators (NBFE) examination for certification consists of 100 multiple choice questions that test the forensic candidates knowledge in 20 forensic domains. Determination of Cutoff Score NBFE Written Examinationīy Ronald W.