This book examines the impact of business incubators on small, high-technology firms" entrepreneurial networks. Previous research has shown that networking (e.g., personal, social, business) by a firm improves the longer term chances of firm survival and growth, specially in the early stages of development. Business incubators, whose purpose is to nurture and grow firms during this sensitive stage, provide key networking services that help the development and growth of these young enterprises. This study examines the effectiveness of business incubators by investigating their networking services. This research proposes an entrepreneurial network typology, consisting of seven networking groups: board of directors, customers, suppliers, trade organizations, financial sources, consultants and advisors, and strategic partners. A set of comparative hypotheses are posed and tested by statistical comparisons of entrepreneurial network variables between a sample of 61 high technology incubator firms (interest group) and a sample of 80 comparable non-incubator firms (control group). Although previous studies have examined issues relating to incubator effectiveness, they have lacked a theoretical framework to address incubators" impact on networks. Additionally, most of the research have been anecdotal, case-based and , therefore, have not been generalizable. Finally, past efforts have not been comparative. This study addresses these shortcomings. The results of the study suggest that business incubators influence a subset of examined networks, specifically, customers, consultants and advisors (public), financial sources (grants and equity capital) and strategic partnerships (R&D and joint ventures). For remaining networks in the typology, statistically significant differences were not found between incubator and non-incubator firms. The study concludes with a number of prescriptive recommendations for business incubator practitioners and stakeholders to improve program effectiveness.