using the guttman scale to define and estimate measurement error in items over time the case of cognitive decline and the meaning of “points lost”使用格特曼量表在项目定义和测量误差估计随着时间的认知能力下降的情况下,u201c分输了u201d的意思.pdfVIP

Using the Guttman Scale to Define and Estimate Measurement Error in Items over Time: The Case of Cognitive Decline and the Meaning of ‘‘Points Lost’’ 1,2 2,3 4 5 6 Rochelle E. Tractenberg *, Futoshi Yumoto , Paul S. Aisen , Jeffrey A. Kaye , Robert J. Mislevy 1 Departments of Neurology, Biostatistics, Bioinformatics Biomathematics, and Psychiatry, Georgetown University Medical Center, Washington, District of Columbia, United States of America, 2 Collaborative for Research on Outcomes and –Metrics, United States of America, 3 University of Maryland University College, College Park, Maryland, United States of America, 4 Department of Neurology, University of California San Diego, La Jolla, California, United States of America, 5 Layton Alzheimer’s Disease Research Center, Oregon Health Sciences University, Portland, Oregon, United States of America, 6 Educational Testing Service, Princeton, New Jersey, United States of America Abstract We used a Guttman model to represent responses to test items over time as an approximation of what is often referred to as ‘‘points lost’’ in studies of cognitive decline or interventions. To capture this meaning of ‘‘point loss’’, over four successive assessments, we assumed that once an item is incorrect, it cannot be correct at a later visit. If the loss of a point represents actual decline, then failure of an item to fit the Guttman model over time can be considered measurement error. This representation and definition of measurement error also permits testing the hypotheses that measurement error is constant for items in a test, and that error is independent of ‘‘true score’’, which are two key consequences of the definition of ‘‘measurement error’’ –and