This chapter emphasizes the relevance of contextual models to the growth of criminological theory. Such models present problems of theoretical specification, measurement, and analysis that are not present in studies that focus on only a single level of analysis and, consequently, only a few studies have addressed the contextual effect issue. While the results that have emerged tend to support the contextual hypothesis, the magnitudes of some of these effects have been fairly weak. Because of the sporadic nature of these studies and the variety of study designs and analytic techniques, any general conclusions concerning the nature of contextual effects would be very premature. Nevertheless, most of the major contemporary criminological paradigms are at least implicitly contextual, and the development of a full criminology depends on resolution of the problems mentioned above. Footnotes, references