Comparative study of software metrics' aggregation techniques

While software metrics are commonly used to assess software maintainability and study software evolution, they are usually defined on a micro-level (method, class, package). Metrics should therefore be aggregated in order to provide insights in the evolution at the macro-level (system). In addition to traditional aggregation techniques such as the mean, recently econometric aggregation techniques such as the Gini index and the Theil index have been proposed. Advantages and disadvantages of different aggregation techniques have not been evaluated empirically so far. In this paper we present the preliminary results of the comparative study of different aggregation techniques.