an easy to use program that computes the correction given by Levy (1967) for correcting a short vs long form test correlation for spurious inflation due to shared error variance. This program is useful for either teaching purposes or for anyone trying to develop a short form test from a long form. Also, the program contains on-line help - which outlines the problem, explains the solution, and provides the 1967 Levy equation (and paper reference).

28th June, 2005
Greatly enlarged on-line help with many examples and discussions concerning short-form composition and associated standard deviation issues (subset length and standard deviation monotonicity and the exceeding of the long-form standard deviation (SD) with that from a short form). Also, cleaned up the user interface and allowed for the case where the part SD equals or exceeds the long-form SD (although two kinds of warning are given) - on the first occasion a large message about the problem then on subsequent occasions just a small reminder and direct online help link. Written and compiled in Delphi 2005 - with HTML help.

Download and Installation Information
The installation file is 6.8Mb in size. It's a zipped archive of a single installation setup file which contains a large online help file (with a fair amount of graphics and tables hence the rather large installation file). The setup file is available here.