Fig. 8

QUEST fit map (McKay 2000a p.222). This figure shows the fit statistics (listed horizontally .56 to 1.40 is the infit mean square); the asterisks represent the magnitude of the fit statistic for the test-item on the same line. The test-items that fall between the two vertical dotted lines (thresholds .77 to 1.30) are considered acceptable; test-items to the left overfit (see test-item 34), indicating duplication or having limited contribution. Underfit test-items to the right of the threshold lines, measure something else and need rewording