Each version had two categorical response items and two metric response items.
This metric illustrates how closely related measured items are as a group.
14 In theory, and similar to the graduations of a metric ruler, items should have the same difficulty for all diagnostic groups, regardless of the disease being measured.
This metric scores an item set based on the physical distance of the typical items within the set; i.e. items that are far apart can be said to have a low cohesion, while items that are proximal have a high cohesion [ 20].
Moreover, because of the diverse cultural backgrounds of students from the participating countries in this study, we leave open the hypothesis whether there is support for an invariance of factor loading (metric invariance), and item intercept (scalar invariance) across the countries or educational systems.
This method of parceling was recommended by Little et al. (2002) when all items are answered on the same metric and when items can be considered unidimensional (for example, as verified through previous studies involving exploratory factor analysis).
Table 2 shows descriptive and metric analysis; all items had averages greater than 2 (with the exception of item 15: M = 1.70, SD = 0.84) revealing values in the upper levels.
To measure differences in recall of categorical and metric information, four items included categorical options (for example, "A. Triassic…), and four included numeric magnitude response options (for example, "A. 230 million years ago…).
On the other hand, the use of polychoric correlation matrixes for the estimation of the factor analysis models resulted efficient and made it possible to incorporate both the weightings of the sample subjects and the ordinal metric of the items.
However, whereas all items were metric invariant at cycles 4 and 7, only three items were also scalar invariant at cycle 4 (items C, E and F) or cycle 7 (A, B and E).
Another refinement would be to examine the occurrence of metric and scalar differential item functioning according to the mental state or educational status of the elderly.
