软件工程评估和管理英文讲义EASE9.ppt

1、Empirical Assessment in Software Engineering,CSEM01SE Evolution effort may be wasted. Evaluation is difficult as research solutions often use technology not commonly available in industry. Often, delays to evaluation mean the problem researchers are solving has evolved through changes in business pr

2、actice, technology, etc. Transfer is difficult because industry has little confidence in the proposed research solution.,Industry-as-Laboratory,Problem V2,Problem V1,Problem V3,Problem V4,Research Solution V1,Research Solution V2,Research Solution V3,Research Solution V4,Industry-as-Laboratory empha

3、sizes Real Case Studies,Real-world case studies have advantages over the lab. Scale and complexity - small, simple (even simplistic) cases avoided - these often bear little relation to real problems. Unpredictability - assumptions thrown out as researchers learn more about real problems Dynamism - a

4、 real case study is more vital than a textbook account The real-world complications of industrial case studies are more likely to throw up representative problems than research laboratory examples influenced by the researchers preconceptions.,Need to consider Human/Social Context in SE research,Not

5、all solutions in software engineering are purely technical. There is a need to examine organisational, social and cognitive factors also. Many problems are people problems, and require people-orientated solutions.,Theoretical SE research,Although it is still appropriate that there is innovative, blu

6、e-skies research in Software Engineering, what really needs to be rewarded is practical, industry-led studies. These various forms of research ideally complement one another; neither is particularly successful if it ignores the other. Too industrially focused research may lack adequate theory, just

7、as too academically focused research may miss the practice.,Research models for SE,Problem highlighted by Glass*: Most SE Research in 1990s was Advocacy Research. Better research models needed. The software crisis provided the platform on which most 90s research was founded. SE Research ignored prac

8、tice, for the most part; lack of practical application and evaluation were gapping holes in most SE research. Appropriate research models for SE are needed. * Robert Glass, The Software -Research Crisis, IEEE Software, November 1994,Methods underlying Models,Scientific method Engineering method Empi

9、rical method Analytical method,Scientific Method,Observe real world,Propose a model or theory of some real world phenomena,Measure and analyse above,Validate hypotheses of the model or theory,If possible, repeat,Engineering Method,Observe existing solutions,Propose better solutions,Build or develop

10、better solution,Measure, analyse, and evaluate,Repeat until further improvements are impossible,Empirical Method,Propose a model,Develop statistical or other basis for the model,Apply to case studies,Measure and analyse,Validate and then repeat,Analytical Method,Propose a formal theory or set of axi

11、oms,Develop a theory,Derive results,If possible, compare with empirical observations,Refine theory if necessary,Need to move away from purely analytical method,The analytical method was the most widely used in mid-90s SE research, but other methods may be more appropriate in some SE research. Good r

12、esearch practice combines elements, and examples, from all these approaches.,Four important phases for any SE research project (Glass),Informational phase - Gather or aggregate information via reflection literature survey people/organization survey case studies Propositional phase - Propose and buil

13、d hypothesis, method or algorithm, model, theory or solution Analytical phase - Analyze and explore proposal leading to demonstration and/or formulation of principle or theory Evaluation phase - Evaluate proposal or analytic findings by means of experimentation (controlled) or observation (uncontrol

14、led, such as case study) leading to a substantiated model, principle, or theory.,ICSE 2002 types of study,Analysis Evaluation Experience Example Persuasion (blatant) Assertion “the most successful studies were based on analysis and real-world experience” Writing Good SE Research Papers, Mary Shaw, CMU, 2002,Evidence Based Software Engineering for Practitioners*,Convert a problem into an answerable question Search the literature for the best available evidence Critically appraise the evidence validity, impact, applicability Integrate the