The types of data and methods of collection a law enforcement agency uses will depend upon what questions the agency wants to answer. For example, if an agency wants to determine citizen satisfaction with enforcement services, it may conduct an annual survey via phone, mail or Internet. If the goal is to evaluate the effectiveness of an agency's community-policing effort in a target area, the agency may collect various types of data (e.g., crime data, arrest data, calls for service), with designated reporting periods (e.g., weekly, monthly). That can be combined with a long-term measurement strategy to determine impact. In addition, the scope of a measurement effort will depend on resources available.
To do evaluation well, an agency must make a commitment to acquiring the expertise needed to collect and analyze data. It must build the capacity to measure organizational performance as a standard practice. This can occur by hiring social scientists to work in an agency's Planning and Resource Unit (see http:// leoprd.org) or collaborating with academic partners. The benefits are likely to be: