ERIC Number: ED434115
Record Type: Non-Journal
Publication Date: 1999
Reference Count: N/A
Detecting Differential Rater Functioning over Time (DRIFT) Using a Rasch Multi-Faceted Rating Scale Model.
Wolfe, Edward W.; Moulder, Bradley C.; Myford, Carol M.
This paper describes a class of rater effects that depict rater-by-time interactions. This class of rater effects is referred to as differential rater functioning over time (DRIFT). This article describes several types of DRIFT (primacy/recency, differential centrality/extremism, and practice/fatigue) and Rasch measurement procedures designed to identify these types of DRIFT in rating data. These procedures are applied to simulated data and are shown to be useful in classifying raters as being aberrant or nonaberrant about 95% of the time for primacy, recency, and differential centrality and extremism, particularly for moderate or larger effect sizes. Rates of correct classification for practice and fatigue were lower (about 89%) and statistical power exceeded 0.50 only with very large effect sizes. Type I error rates (i.e., incorrect nomination) were near expected levels in all cases. (Contains 10 tables and 32 references.) (Author/SLD)
Publication Type: Reports - Descriptive; Speeches/Meeting Papers
Education Level: N/A
Authoring Institution: N/A