Using students as subjects - a comparative study of students and professionals in lead-time impact assessment

In many studies in software engineering students are used instead of professional software developers, although the objective is to draw conclusions valid for professional software developers. This paper presents a study where the difference between the two groups is evaluated. People from the two groups have individually carried out a non-trivial software engineering judgement task involving the assessment of how ten different factors affect the lead-time of software development projects. It is found that the differences are only minor, and it is concluded that software engineering students may be used instead of professional software developers under certain conditions. These conditions are identified and described based on generally accepted criteria for validity evaluation of empirical studies.