The Programme for the International Assessment of Adult Competencies (PIAAC) has been planned as an ongoing program of assessment. The first cycle of the assessment has involved two "rounds." The first round, which is covered by this report, took place over the period of January 2008-October 2013. The main features of the first cycle of…

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…