This report, which is based on an invited presentation given at the 2015 meeting of the Association of Test Publishers, is a response to the continuing proliferation of scale linking studies that have occurred since the publication of "Uncommon Measures" in 1999.The report has four parts. First, I restate the conclusions made in…

Maintaining comparability of test scores is a major challenge faced by testing programs that have almost continuous administrations. Among the potential problems are scale drift and rapid accumulation of errors. Many standard quality control techniques for testing programs, which can effectively detect and address scale drift for small numbers of…

This paper provides a history of ETS's role in developing assessment instruments and psychometric procedures for measuring change in large-scale national assessments funded by the Longitudinal Studies branch of the National Center for Education Statistics. It documents the innovations developed during more than 30 years of working with…