Early life cycle design: Methods for visualising the object-oriented design process and the impact of task characteristics on design quality Master of Science Thesis

The object-oriented methodology is now used more and more in industry without scientific evidence supporting its claimed benefit of applicability to a wide range of tasks. Prior research in human problem solving suggests that if the characteristics of the task and tool match, a better result is achieved than if there is a mismatch. To investigate this, we replicated an experiment by having two groups of subjects solve two different tasks; one object-oriented and one process-oriented. The prediction that the object-oriented methodology should match better with the object-oriented task and result in better performance was not supported; there was no significant difference in the quality of the solutions from the two groups. Even though the type of task did not influence the quality of the solutions, there were differences between the best and worst performances among the subjects. To gain insight into how these different solutions were achieved, the design process was explored by developing methods for visualisation of the design process. In this exploratory research we found two useful models to visualise design growth and design status. Design growth shows how the quality of the solution grows with time and design status show the status of the user; if he/she is working with the structure-part or the behaviour-part of the task. To be able to use these models, fine grain data from the design process was needed. This was possible through the use of an instrumented CASE-tool that captured every action made by the user. When the models were used on our data and the best solutions compared with the worst, the findings indicated that modeling all of the structure-part of the task before modeling the behaviour-part gives a higher quality solution. First of all we would like to thank our two supervisors Prof. for their support and positive feedback during the writing of the thesis. A special thanks to Prof. Ross Jeffery for helping us with our English and guiding us through problems and difficulties. Thanks to Prof. Claes Wohlin (from Lund University, Sweden) for establishing the link to Prof. Ross Jeffery and therefore enabling us to experience this enriching semester in Sydney. Thanks to Dr. Andrew Brooks (from University of Strathclyde, Scotland) for the initial guidance and thanks to the students participating in the experiments. We also thank Derek Renouf and Fiona Walkerdon at Adaptive Arts for the instrumentation of Simply Objects which was a key item …