A New Approach to Avoiding Problems of Scale in Interpreting Trends in Mental Measurement Data

Extracting policy‐relevant information from large national surveys of educational achievement is ordinarily a nontrivial task. It is made more treacherous when the data are expressed on scales that are not uniquely determined. The paper begins with a critical analysis of a recent attempt to interpret the findings on reading achievement obtained by the National Assessment of Educational Progress (NAEP). It then describes a new approach to the quantification and interpretation of change and demonstrates its appropriateness for repeated cross‐sectional designs such as NAEP. Limitations imposed by the survey design and the nature of the measurements are highlighted