Computer Assisted Accummulation of Reliability Information

Abstract

A computer program which creates and stores a cummulative item covariance matrix upon each administration of an instrument is described. Program input is the former item covariance matrix as well as subjects' item scores from the new administration. Thus storage of all the subjects' item scores, and recalculation of previous subjects' contribution to item covariance upon each new administration is avoided. As all classical psychometric information including reliability can be calculated from the item covariance matrix, use of this program would facilitate keeping a constant log on reliability in situations in which the test is administered to different groups over a period of time. Alternately, reliability could be calculated after a respectable size sample is accummulated.