Paper Summary

Comparisons of Three Strategies for Addressing Missing Data in a Graded Response Model

Tue, April 17, 12:25 to 1:55pm, Vancouver Convention Centre, Floor: First Level, East Ballroom C

Abstract

Three strategies for addressing missing data on a summated rating scale analyzed with the graded response model are compared, namely complete case analysis, ordered categorical logistic regression imputation with nose, and multiple imputation. If data are Missing Completely at Random (MCAR), the differences among the three methods are negligible. However, if data are Missing at Random (MAR), both complete case analysis and ordered categorical logistic regression produce biased item and ability parameter estimates. Multiple Imputation is a practical and conservative method of choice, since we never know whether data are MAR or MCAR.

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