Rasch scaling

This paper describes a methodology for exploring the validity of the Rasch scaling procedure in relation to a multiple-choice test of reading Chinese as a foreign language. The validation procedure involved a post hoc content analysis of test items to identify factors which the research literature on early reading indicated were likely to be related to item difficulty. A comparison was then made between these difficulty factors and the item-difficulty ranking produced by a Rasch analysis of test items. The analysis revealed that the dimension mapped out by the Rasch scaling (and to some extent the corresponding wording of the reporting descriptors) does indeed reflect certain elements thought to be related to early reading ability.