All crime control activities should be periodically evaluated to determine their effectiveness, so that adjustments and revisions in law enforcement programs may facilitate the most-cost-effective use of police resources. Crime statistics, an important indication of crime prevention effectiveness, should be as accurate and up-to-date as possible. Computer systems can aid speed, accuracy, and analysis in crime data processing. Analysis of crime statistics should be conducted daily to indicate crime trends in various areas. Appropriate formal reports should be issued regularly. Analysis should show increases and decreases by type of crime, area, race, and age groups. Another general area for measuring the effectiveness of crime prevention is indication of public confidence and support. This can be shown in the number of citizen letters of commendation to the department and the press, increases in the public's crime reporting, and the number of grievances lodged against police. Court statistics on the number of cases prosecuted and their outcomes can show the effectiveness of police investigative efforts. Surveys of public attitudes toward crime and citizen efforts to combat crime through target hardening and the mounting of character-building programs for children and youth can also show whether specific police efforts to involve citizens in crime prevention programs are effective. A list of data items to be included in a police information system is provided.