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…

A procedure is described for estimating the reliability and conditional standard errors of measurement of scale scores incorporating the discrete transformation of raw scores to scale scores. The method is illustrated using a strong true score model, and practical applications are described. (SLD)

Effects of passage and item-scrambling on equipercentile and item-response theory equating were investigated using 2 scrambled versions of the American College Testing Program Assessment for approximately 25,000 examinees. Results indicate that using a base-form conversion table with a scrambled form affects the individual examinee level. (SLD)