jimsick at iname.com
Fri Nov 2 19:19:30 EST 2007
To get back to Anthony's original question:
> *Is replicating Fan's research worthwhile?
As I recall, Fan found that 30% of the items did not fit the Rasch
model, which she interpreted as a weakness of the model in accounting
for the variance in the data. I think it would be quite interesting if
someone replicated this study and:
1. Systematically deleted misfitting items until a set with acceptable
fit was derived
2. Compared the Rasch measures constructed from the reduced item set
with raw, 2-PL, and 3-Pl scores of the original data set. And most
3. Conducted a thorough qualitative assessment of the deleted and
retained items in order to . .
4. Discuss the implications for how we name or re-name this variable,
and/or revise our theoretical description of the "new" construct.
Of course, the score comparisons then become fruits and oranges, but
that's the point. And would the new measures be appreciably different?
That is an interesting empirical question.
J. F. Oberlin University
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