The following ASNT NDT Level III exams are accredited by the ANSI National Accreditation Board (ANAB) in accordance with the international standard ISO/IEC 17024:2012 Conformity Assessment - General Requirements For Bodies Operating Certification Of Persons: Basic, ET, MT, PT, RT, UT, and VT. The ISO/IEC 17024:2012 standard is recognized worldwide and requires frequent auditing by ANAB to ensure all requirements are met, including fairness, reliability, and validity (psychometrics).
Psychometrics is the study of the construction and validation of questionnaires and tests with guidelines found in the Standards for Educational and Psychological Testing, developed jointly by the American Educational Research Association (AERA), American Psychological Association (APA), and National Council on Measurement in Education (NCME).
ASNT Certification Services LLC develops and maintains all ASNT examinations using psychometric principles to ensure that they are fair, valid, reliable, defensible, and compliant with accreditation requirements (ANAB ISO/IEC 17024:2012). All questions are developed on the subject matters listed in the topical outlines (or “body of knowledge”) found in ANSI/ASNT CP-105: ASNT Standard Topical Outlines for Qualification of Nondestructive Testing Personnel. All reference materials used to develop examination items are publicly available. Once an item is developed, it is evaluated by a committee of subject matter experts (SMEs) certified in the applicable test method to ensure that the item content is valid.
As part of the development process, an examination specification is established stating the number of items on an exam per section of the body of knowledge. This specification becomes the blueprint and is used every time a new examination form (test) is created and ensures that each exam form assesses candidates on the same percentage of items per subject category.
Exam forms consist of a set number of scored multiple-choice questions, including some that are pretest questions. The pretest questions are not counted in the scoring of the examination. They are distributed among the scorable questions and will be used for statistical purposes only.
To set an objective, criterion-based passing score (a cut score) the Angoff or Item Response Theory (IRT) model is followed. The Angoff and IRT models are generally accepted psychometric procedures widely used by many certification programs to set a defensible passing score. ASNT exams are typically in the 70% to 80% range.