[Rasch] Unidimensionality

Trevor Bond trevor.bond at jcu.edu.au
Thu May 8 09:52:10 EST 2008

Ferguson wrote about this is 1941;
Ferguson, G. A. (1941). The factorial interpretation of test 
difficulty. Psychometrika, 6(5), 323-330.

and it was ignored almost ever since

At 4:13 PM -0400 5/7/08, Michael Lamport Commons wrote:
>Life is more complected.  Let us say one is scaling difficulty of 
>tasks.  One generally will get a single dimension in Rasch but 2 or 
>more dimensions in a factor analysis if ... difficulty is made up of 
>order of hierarchical complexity and also the number of operations 
>such as the number of numbers added.  Difficulty can be seen as one 
>dimension or two depending on how much you know what the more gross 
>variable consists of.
>Michael Lamport Commons

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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://mailinglist.acer.edu.au/pipermail/rasch/attachments/20080508/f75430ed/attachment.html 

More information about the Rasch mailing list