When there are missing data, subsets of the observations may not be measurable with other subsets. For instance, Person sample A responds to Test Form A, and Person sample B responds to Test Form B. If there are no common items nor common persons, combining these two datasets into one analysis will produce two disconnected subsets of responses.
SUBSETS= Yes performs subset and connectivity detection.
SUBSETS = No bypasses subset detection.
When subset detection is activated, "Probing Data Connection" displays in the Winsteps analysis window.
PROBING DATA CONNECTION: to skip out: Ctrl+F - to bypass: subset=no
>=====================================<
Consolidating 8 potential subsets pairwise ...
>=====================================<
Consolidating 8 potential subsets indirectly pairwise ...
>=====================================<
Warning: Data are ambiguously connected into 8 subsets. Measures may not be comparable across subsets.
Subsets details are in Table 0.4
Subsets are reported In Table 0.4 if any are discovered.
TABLE 0.4 Example of subset reporting
SUBSET DETAILS
SUBSET 1 OF 2 ITEM AND 2 PERSON
ITEM: 2-3
PERSON: 2-3
SUBSET 2 OF 2 ITEM AND 2 PERSON
ITEM: 4-5
PERSON: 4-5
SUBSET 3 OF 1 PERSON
PERSON: 6
SUBSET 4 OF 2 ITEM AND 2 PERSON
ITEM: 7-8
PERSON: 7-8
SUBSET 5 OF 2 ITEM AND 2 PERSON
ITEM: 9-10
PERSON: 9-10
SUBSET 6 OF 2 PERSON
PERSON: 11-12
SUBSET 7 OF 3 PERSON
PERSON: 13-15
SUBSET 8 OF 1 ITEM
ITEM: 6
Subsets are also shown to the right of the measure tables, Table 14.1, Table 18.1, etc.
