RMT 16:1 Quotations and Notations
"When schemes are laid in advance, it is surprising how often the circumstances fit in with them."
Sir William Osler (1849-1919)
"If the facts don't fit the theory, change the facts."
Attributed to Albert Einstein (1879-1955)
Too Many Factors?
"Therefore, one might expect the emergence of only one factor when a factor analysis would be performed on all newly defined subsets [of unidimensional items]. However, factor analysis of the newly defined subsets yielded two factors. Further inspection of the factor plot showed that the emergence of a second factor could be considered as an artefact due to the skewness of the subset scores."
Van der Ven, A.H.G.S., & Ellis, J.L. (2000). A Rasch Analysis of Raven's Standard Progressive Matrices. Personality and Individual Differences, 29 (1), 45-64.
"The most valuable contribution to the area of tests of fit for Rasch models in recent years has been the recognition by some psychometricians that there is no such thing as a final `fit' of data to the model and hence that no one test is ever likely to be complete. Appreciation of this point still needs to be given much wider circulation among workers in the field. Then there will be less of a tendency to reject data sets (or the model) outright, simply because one test failed to show `fit'. Implicit in this perspective is the assumption that there is as much to be learnt about a data set from the responses which misfit as there is from those which do fit."
Graham Douglas (1982) Issues in the fit of data to psychometric models. Education Research and Perspectives, 9:1, p. 43.
RMT 16:1 Quotations and Notations. … 16:1 p.860ff.
RMT 16:1 Quotations and Notations. … Rasch Measurement Transactions, 2002, 16:1 p.860ff.
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