Common-Person Equating with the Rasch Model

The effects of the violation of local independence assumption on the person measures under the Rasch model

Local independence of test items is an assumption in all Item Response Theory (IRT) models. That is, the items in a test should not be related to each other. Sharing a common passage, which is prevalent in reading comprehension tests, cloze tests and C-Tests, can be a potential source of local item dependence (LID). It is argued in the literature that LID results in biased parameter estimation ...

Person parameter estimation in the polytomous Rasch model

An important task in psychometric measurement is to identify the skills of persons, by accounting the difficulty degree of item responses in questionaries. The Item Response Theory (IRT) is the base for a valid measurement of the skills and the Rasch Model a well established probabilistic model, in the implementation of the theory. More recent extensions of the Rasch Model include the Partial C...

The Rasch Model for Test Construction and Person Measurement

Adjusted Rasch person-fit statistics.

Two frequently used parametric statistics of person-fit with the dichotomous Rasch model (RM) are adjusted and compared to each other and to their original counterparts in terms of power to detect aberrant response patterns in short tests (10, 20, and 30 items). Specifically, the cube root transformation of the mean square for the unweighted person-fit statistic, t, and the standardized likelih...

Rasch simultaneous vertical equating for measuring reading growth.

The longitudinal measurement of ability growth requires that the measures that are taken at the various time points be obtained using the same yardstick. Tests given for this purpose, therefore, need to be equated. The popular practice still in use for the purpose of equating tests, is the grade-equivalent. This paper compares the observation of children's growth in reading using grade-equivale...