Comparative Analysis

Comparative analysis answers questions about how and why a system will react to perturbations of its parameters. For example, comparative analysis can explain why the period of a spring/block system would increase if the mass of the block were larger. This paper formalizes the problem of comparative analysis and describes a solution technique, differential qualitative analysis; the technique only works if the system can dynamically change perspectives when it compares the values of parameters over intervals. This paper shows how perspectives can be used for comparative analysis, summarizes a soundness proof for the technique, demonstrates incompleteness, describes a working implementation, and presents experimental results.