In this chapter, we compare the findings from causal maps derived from semi-structured interviews with that obtained from survey respondents, using a data set originally constructed to characterize object-oriented (OO) software development expertise. To compare the results, we invoke three different theories to capture evoked concepts in the interviews, but discover one theory provided more robust theoretical constructs in embracing the evoked concepts. The survey responses were factor analyzed to explore if the factor structure matched the structure derived from revealed causal maps. Although there was significant similarity between the results, the survey yielded more factors than predicted by the theory. The lessons learned from this process are discussed.