Psychological Complexity Measure

at the Domain Analysis Phase

of an Object-Oriented System

Sanjay Kamath

December 6, 1994

Abstract

A psychological complexity measure developed at Clemson University, called the Permitted Interactions (PI) measure, uses design information to calculate the psychological complexity as a measure of effort. However there is a general demand for measures that can use information present at earlier phases. Following this requirement the measure reported here estimates complexity at the domain analysis phase which is the earliest development phase in an objectoriented software process. Psychological complexity relates to the cognitive load imposed on the developers of the software system which is in turn directly related to the time to completion of the development process. We define a measure called Permitted Collaborations (PC) which measures the psycholgical complexity from a set of CRC cards that represents a domain. The measure can however be used on any object-oriented representation like OMT diagrams that provide equivalent information. The measure has been found to be responsive to system changes and we show that the measure can aid the developers in selecting the right class decomposition when there are conflicting choices. Empirical validation is done to correlate the values given by PI and PC for a set of classes and the result show positive correlation.