@dennyborsboom "The sum score is not just a poor man’s test score but provides a defensible ordinal approximation of the latent variable under surprisingly general conditions."
On classical test theory CTT
"the crucial insight is that CTT can operate in the absence of
assumptions regarding the test’s dimensionality or factorial composition"
"What CTT did right, however, is provide a solid theoretical framework for determining the
degree to which test scores are influenced by random error. "



