MY REPLY
All it seems to imply is that the assessor's grids are defining a high
dimensional world than the candidates are presenting. In other words assessors
can conceive of a candidate being good on evaluative construct 1 but not good
on evaulative construct 2. However there are none or very few candidates who
actually present with that combination. You could contrast the politically
correct multidimensionality of the assessors with the one-dimensional reality
of the candidates. I think it is pointless the go the full empirical mile
and start to argue that the assessor's view of the world does not exist
because candidates do not fill all its parts.
The only way to make assessor's multi-dimensionallity to work is to have them
think in (dare I say) normative terms. Compared with someone who has achieved
general ability X, this person is above or below on a series of constructs.
Then perhaps you would gain something multi-dimensional. In other words you
are needing partial correlations corrected for candidate ability. However
rather than trying a technical statistical fix, try changing the judgements.
Dr Stephen K Tagg
Department of Marketing
(been analyzing grids for 20 years - mainly with MDS procedures...)