Section 22.6. CONCLUSION

22.6. CONCLUSION

We conducted an exploratory comparative study of three concern elaboration tools on three different tasks and systems. Based on the results and our experiences during the system, we synthesized three design recommendations for developers of future concern elaboration tools. These recommendations may also apply to tools, such as browsers within integrated development environments, which are not specifically intended for the task of concern elaboration. We stated our findings as recommendations since, undoubtedly, there is a cost to tool designersand possibly tool usersin supporting the recommendations. For instance, support for following control flow can be achieved using parsing and control flow graph techniques; these techniques entail a cost in the tool implementation and in the runtime of the tool. For a tool designer targeting, and a user working within, an integrated development environment, the costs of such an approach depend on the resources provided by the environment and may be acceptable. As another example, a tool that allows the user to control the extent of a concern places the onus on the user to determine and evaluate completeness of a concern for the task at hand. A user working on a safety-critical system may prefer a tool with a higher runtime cost that provides a more complete impact analysis. The design recommendations we have stated help to expand our understanding of the design space for concern elaboration tools. Ultimately, tools designers must determine appropriate points in the design space that are effective for software developers.

The results of our study also caused us to hypothesize that a concern can consist of three parts: a core part, an interface part, and a series of execution points. A characterization of the form of a concern can help researchers tackling problems in software maintenance and aspect-oriented software development.

As with any exploratory study, our results need to be subjected to further investigation. The results of this study provide a basis for a more thorough study of the effectiveness of concern elaboration tools and hypotheses for further empirical investigations of concerns.