Object technology (OT) is a relatively new branch of information technology (IT) that is based on the object paradigm. A major component of OT is object-oriented systems development (OOSD), a process that many believe to be far superior to conventional systems development (CSD) (Rumbaugh et al. 1991, Coad and Yourdon 1991, Booch 1994, Coleman et al. 1994, Jacobson et al. 1995). One concern with OOSD is the shortage of hard empirical evidence either for or against it. The purpose of this study is to explore the validity of many beliefs about OOSD using a large random sample of experienced systems developers. Additionally, beliefs held by developers who are experienced in OOSD are compared to those who are not. Through such a study, the most significant and substantial beliefs can be identified, and the effect of experience in OOSD on such beliefs can be determined.