The Programme for International Assessment of Adult Competencies (PIAAC) will establish technical standards and guidelines to ensure that the survey design and implementation processes of PIAAC yield high-quality and internationally comparable data. This document provides a revised version of the technical standards and guidelines originally…

Item response theory (IRT) methodology is introduced as a tool for improving assessment instruments used with people who have disabilities. Need for this approach in rehabilitation is emphasized; differences between IRT and classical test theory are clarified. Concepts essential to understanding IRT are defined, necessary data assumptions are…

This book discusses constructing variables and making measures. It begins by outlining the qualities a number must meet before it qualifies as a measure of something. The basis is the measurement philosophy of G. Rasch. The first requirement for making good measures is good raw material. To achieve the possibility of comparisons, the data must…