INDEXED= summarize response strings for estimation = Yes

INDEXED=Yes - Winsteps scans the data rows (persons) and builds an index of persons who responded to the same items and achieved the same raw score. Then each index entry is estimated. This can speed up analysis if many persons were administered the same items and obtained the same score. But building the index takes time.

 

INDEXED=No - Winsteps estimates each person separately.

 

The very small differences in estimates between the INDEX= settings are due to computer floating-point imprecision. INDEXED=No requires more floating=point additions than INDEXED=Yes (when successful).Enter topic text here.

 

Example 1: 2,000 persons take the same 10-item test. We expect many persons to achieve the same score on the same items. INDEXED=Yes will speed up estimation.

 

Example 2: 2,000 persons take an adaptive test with an item bank of 200 items. Few people achieve the same score on the same items. INDEXED=Yes will slow down estimation. Set INDEXED=No.