Early Lifecycle Work: Influence of Individual Characteristics,Methodological Constraints, and Interface Constraints

TLDR: It is concluded that studies comparing extreme programming approaches with conventional CASE tool approaches are needed to help determine if the struggle to understand the constraint environment at a high level of abstraction is worthwhile or not, and that every subject-based experiment should consider and understand the performance of individuals.

Abstract: This paper reports the results of an experiment undertaken for the CADPRO (Constraints And the Decision PROject) project. Subjects with varied experience produced data flow diagrams (DFDs) using a DFD tool generated by CASEMaker, a meta-CASE tool. Half the subjects received routine notice of instances of internal (as opposed to hierarchical) methodological constraint violations via an unobtrusive window whilst the other half did not. The DFD tool automatically recorded subjects' delivery and constraint profiles. Video records, observer notes, and subject debriefings were also used to yield other performance data. While evidence was found in support of the research model underpinning the CADPRO project, the model needs to be revised to take into account the affects of human-computer interface constraints and the different speeds with which people work. We learnt an important lesson about subject randomisation, which is not to assume that all subjects can be treated alike if they share the minimum necessary experience thought required of the problem. We believe it is important for every subject-based experiment to consider and understand the performance of individuals. Because of the complexity of constraint environments in CASE tools we also conclude that studies comparing extreme programming approaches with conventional CASE tool approaches are needed to help determine if the struggle to understand the constraint environment at a high level of abstraction is worthwhile or not. Further experiments, possibly replication variants of this one, are needed to help validate our interpretations.