Improved Metrics for Encapsulation Based on Information Hiding

The contribution of metrics to the overall objective of software quality is understood and fully recognized by the software engineering community in general. In the design and development of object-oriented software we should keep information such as attributes and methods in a module or class invisible to external environment as possible. Although Method Hiding Factor (MHF) and Attribute Hiding Factor (AHF) in a suite of metrics MOOD have been adopted to measure the degree of information hiding. They are not sufficient, because they are method and attribute level that are only finely granular and they are incomplete. The information hiding metrics of class and system which are coarsely granular and medium granular should be needed. In this paper, improved metrics for encapsulation based on information hiding is proposed to satisfy the above need of different grains. The new measures are applied in an experiment to obtain results, and its validity, completeness and accuracy are proved. The new metrics will be impact on design and development of object-oriented software.