1. International Workshop on Future Software Technology 2005/11/8 - 10 Two approaches in Empirical Software Engineering Kenichi Matsumoto Nara Institute of Science and Technology

2. 2 International Workshop on Future Software Technology 2005/11/8 - 10 2 Two approaches Goal-driven Approach (GDA) Goal is prescribed and empirical data is collected to achieve such specific goal. Model to clarify relationship between the goal and data is needed. GQM Model, ISO Measurement Information Model Data-driven Approach (DDA) By using large amount of stored data, the relationship among software product, process, and resource is revealed. Visualization and data mining techniques are needed. Project Visualization, Association Analysis

3. 3 International Workshop on Future Software Technology 2005/11/8 - 10 3 Goal/Question/Metric (GQM) Model V. R. Basili and D. M. Weiss: A methodology for collecting valid software engineering data, IEEE Transactions on Software Engineering, Vol.SE-10, No.6, pp.728-738, 1984. Question to evaluate Goal Data set to answer Question Measurement Goal

4. 4 International Workshop on Future Software Technology 2005/11/8 - 10 4 Association Analysis Useful method for discovering interesting relationships hidden in large data sets. The uncovered relationships can be represented in the form of association rules; X -> Y: “60% of bug reports have “Change Request” class” -> “the requirements are unstable” The strength of an association rule can be measured in terms of its support and confidence. Support: how often a rule is applicable to a given data set. Confidence: Conditional probability P(Y|X).

5. 5 International Workshop on Future Software Technology 2005/11/8 - 10 5 Integration of Two Approaches Data-driven Goal-driven ISO MI Model GQM Model Association Analysis Visualization Case-Based Reasoning Conventional metrics Multi-Dimensional Scaling Integrated Empirical Approach in SE Threshold, Rule, Scale, … Analysis Model Values New metrics

6. 6 International Workshop on Future Software Technology 2005/11/8 - 10 6 GQM with Association Rules Ｍｏｄｅｌ （Ｑｕｅｓｔｉｏｎ） if ( FCM > 1.0 and (LCC/LOC > 5%) and (60% of bug reports have “Change Request” class ) then the requirements are unstable Ｍｅｔｒｉｃ FCM: Cumulative number of changed files / total number of files currently in the system. LCC: the number of lines of code changed. LOC: the number of lines of code. Replace them with "Association Rules” discovered in data sets collected in your project or organization