[Rasch] Unidimensionality

Trevor Bond trevor.bond at jcu.edu.au
Fri May 9 00:59:57 EST 2008

BUT such additional dimensions do not invalidate the use of the Rasch 
scores, as these have already separated out the ability dimension of 

oh - but they do invalidate it as providing MEASURES /(Rasch scores)

N is the sufficient statistic for ability only to the extent that the 
data fit the model.

remaining structures in the residuals tell us that the Rasch 
dimension is not all (most / enough) of what is in the data set.
Trevor G BOND Ph D
Professor and Head of Dept
Educational Psychology, Counselling & Learning Needs
D2-2F-01A EPCL Dept.
Hong Kong Institute of Education
10 Lo Ping Rd, Tai Po
New Territories HONG KONG
Voice: (852) 2948 8473
Fax:  (852) 2948 7983

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