While score comparability across test forms typically relies on common (or randomly equivalent) examinees or items, innovations in item formats, test delivery, and efforts to extend the range of score interpretation may require a special data collection before examinees or items can be used in this way--or may be incompatible with common examinee…

Context effects are defined as being influences on test performance associated with the content of successively presented test items or sections. Four types of context effects are identified: (1) direct context effects (practice effects) which occur when performance on items is affected by the examinee having been exposed to similar types of…