data(vegetables)
Turn
Cab
Beet
Asp
Car
Spin
S.Beans
Peas
Corn
Thurstone considered five different sets of assumptions about the equality and independence of the variances for each item (Thurston, 1927). Torgerson expanded this analysis slightly by considering three classes of data collection (with individuals, between individuals and mixes of within and between) crossed with three sets of assumptions (equal covariance of decision process, equal correlations and small differences in variance, equal variances).
This vegetable data set is used by Guilford and by Nunnally to demonstrate Thurstonian scaling.
Revelle, W. An introduction to psychometric theory with applications in R. (in preparation), Springer. http://personality-project.org/r/book
thurstone
data(vegetables)
thurstone(veg)
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