Abstract
Over the last few decades, a lot of research has been done to measure software quality including using high-level design metrics to measure the quality of the design. R. C. Martin's metrics are some of the best-known software package metrics. Martin began with a set of object oriented design principles and designed his metrics based on these principles. In this paper we begin with Martin's principles and use them to modify his instability and abstractness metrics which were defined to identify poorly designed packages which are hard to maintain and reuse. We modify Martin's metrics based on the concept of responsibility, our motivation is that packages with different levels of responsibility should have different weights with respect to the instability and abstraction metrics. We present a case study to validate the modified metrics, the comparative study shows the differences between the proposed metrics and Martin's metrics. We found that the proposed instability and abstractness metrics are very promising and lead to improved results.