Behavior Research Methods

, Volume 39, Issue 3, pp 527-530

First online:

CTTITEM: SAS macro and SPSS syntax for classical item analysis

  • Pui-Wa LeiAffiliated withPennsylvania State University Email author 
  • , Qiong WuAffiliated withPennsylvania State University


This article describes the functions of a SAS macro and an SPSS syntax that produce common statistics for conventional item analysis including Cronbach’s alpha, item difficulty index (p-value or item mean), and item discrimination indices (D-index, point biserial and biserial correlations for dichotomous items and item-total correlation for polytomous items). These programs represent an improvement over the existing SAS and SPSS item analysis routines in terms of completeness and user-friendliness. To promote routine evaluations of item qualities in instrument development of any scale, the programs are available at no charge for interested users. The program codes along with a brief user’s manual that contains instructions and examples are downloadable from