This approach has the advantage of addressing immediate concerns rather than "root causes," and it can be tailored to a particular crime type and community, as opposed to crime in general and society at large. Factors influencing crime opportunities available include reduction of the monetary incentives of armed robbery, increased level of surveillance, target-hardening, lifestyle and activity changes, proximity factors, and availability of firearms. One factor detracting from the value of criminal opportunity reduction measures is the assumption that all robbers are rational decision-makers with unlimited resources who carefully evaluate a wide range of possible targets. 27 references.