Formalizing the use of Rasch item fit statistics
Plan: We will send this to Measurement, backup journal is BMC Medical Research Methods or JEBS
The Rasch model (Rasch 1960, Fischer 1995, Christensen 2013) is widely used for scale validation in health, education, psychology, and other fields. Item fit statistics are arguably the most relevant and certainly the most often statistics when testing the Rasch Model because aberrant response patters can produce inaccurate person and item estimates. Several fit statistics have been developed, however the most widely used are the INFIT and OUTFIT mean square item fit statistics (Wright 1979, Wright 1982) that are included in Winsteps (Linacre 2011) and eRm (ref) and the fit residual, Chi-square and ANOVA item fit statistics, that are available in RUMM2030 (ref).