Evaluating object-oriented designs with link analysis

The Hyperlink Induced Topic Search algorithm, which is a method of link analysis, primarily developed for retrieving information from the Web, is extended in this paper, in order to evaluate one aspect of quality in an object-oriented model. Considering the number of discrete messages exchanged between classes, it is possible to identify "God" classes in the system, elements which imply a poorly designed model. The principal eigenvectors of matrices derived from the adjacency matrix of a modified class diagram, are used to identify and quantify heavily loaded portions of an object-oriented design that deviate from the principle of distributed responsibilities. The non-principal eigenvectors are also employed in order to identify possible reusable components in the system. The methodology can be easily automated as illustrated by a Java program that has been developed for this purpose.