Subject matter experts are an important part of the process in developing a defensible exam. There are several ways that their input is required. Here is a list from highest involvement/responsibility to lowest: Serving on the Certification Committee (if relevant) to decide important things like eligibility pathways Serving on panels for psychometric steps like Job […]
One of the most cliche phrases associated with assessment is “teaching to the test.” I’ve always hated this phrase, because it is only used in a derogatory matter, almost always by people who do not understand the basics of assessment and psychometrics. I recently saw it mentioned in this article on PISA, and that was […]
ASC has been empowering organizations to develop better assessments since 1979. Curious as to how things were back then? Below is a copy of our newsletter from 1988, long before the days of sharing news via email and social media! Our platform at the time was named MICROCAT. This later became modernized to FastTest PC […]
Item response theory is the predominant psychometric paradigm for mid or large scale assessment. As noted in my introductory blog post, it is actually a family of models. In this post, we discuss the two parameter IRT model (IRT 2PL). Consider the following 3PL equation (simplified from Hambleton & Swaminathan, 1985, Eq. 3.3). The IRT […]
Item response theory (IRT) is an extremely powerful psychometric paradigm that addresses many of the inadequacies of classical test theory (CTT). If you are new to the topic, there is a broad intro here, where you will learn that IRT is actually a family of mathematical models rather than one specific one. Today, I’m talking […]
Classical test theory is a century-old paradigm for psychometrics – using quantitative and scientific processes to develop and analyze assessments to improve their quality. (Nobody likes unfair tests!) The most basic and frequently used item statistic from classical test theory is the P-value. It is usually called item difficulty but is sometimes called item facility, […]
I’m also frequently asked by people already in the field where they can go to get a graduate degree in psychometrics, especially on sophisticated topics like item response theory…
Have you heard about standard setting approaches such as the Hofstee method, or perhaps the Angoff, Ebel, Nedelsky, or Bookmark methods? There are certainly various ways to set a defensible cutscore or a professional credentialing or pre-employment test. Today, we are going to discuss the Hofstee method. You may also be interested in reading this […]
The Spearman-Brown formula, also known as the Spearman-Brown Prophecy Formula or Correction, is a method used in evaluating test reliability. It is based on the idea that split-half reliability has better assumptions than coefficient alpha but only estimates reliability for a half-length test, so you need to implement a correction that steps it up to […]
Simulation studies are an essential step in the development of a computerized adaptive test (CAT) that is defensible and meets the needs of your organization or other stakeholders. There are three types of simulations: Monte Carlo, Real Data (post hoc), and Hybrid. Monte Carlo simulation is the most general-purpose approach, and the one most often […]
