Figure 2.
Schematic demonstration of good and bad Construct Validity (CV) for 2 reference domains, each described by 3 tasks. Left: very good global CV, performance of tasks within a reference domain are more similar than between-reference domains. The Z-matrix reveals a block-diagonal structure. The observed CV statistic, the difference of mean Z- values within a reference ability to mean Z-values between reference ability values quite high. Right: poor global CV, pairs of tasks within and between reference domains show equal similarity, thus yielding CV value close to zero. The diagonal elements in every Z matrix have been set to zero since for perfect correlation Z becomes infinite.