The National Assessment of Educational Progress (NAEP) uses item response theory (IRT) based scaling methods to summarize information in complex data sets. The necessity of global scores or more detailed subscores, creation of developmental scales for different ages, and use of scale anchoring for scale interpretation are discussed. (SLD)

This chapter gives an overview of the design and statistical and psychometric analysis methods of the National Assessment of Educational Progress (NAEP). The evolution of the NAEP continues to provide challenges to statisticians and psychometricians, as demonstrated in the expansion of the NAEP to the assessment of individual states. (SLD)