DUE TO THE INTERLINKAGE RESULTING FROM SHARED COORDINATE BASES, DATA FROM VARIOUS LOCALITIES OVER WIDE AREAS CAN BE COLLECTED AND MERGED TO PERFORM SPATIAL AND ASPATIAL ANALYSIS. THE VALUES OF THIS SYSTEM ARE DISCUSSED BOTH FROM THE STANDPOINT OF THE DESIRABILITY IN ITS APPLICATION IN THE U.S. AS WELL AS THE IMPLICATIONS OF SUCH AN EFFORT TO CANADIAN EFFORTS IN MAPPING POLICE DATA ON A LARGE SCALE. TERMS ARE DEFINED, BACKGROUND INFORMATION IS PROVIDED, AND TWO GEOGRAPHIC BASE FILE PROJECTS ARE REVIEWED. A GEOGRAPHIC BASE FILE IS A DESCRIPTION FILE WHICH DUPLICATES, IN COMPUTER READABLE FORM, THE INFORMATION FOUND ON A STREET MAP. THIS INFORMATION IS USED TO CROSS-REFERENCE STREET ADDRESSES WITH GEOGRAPHIC AREAS AND ALLOWS THE CODING OF INFORMATION BY COMPUTER. PROGRAM TESTING IS DISCUSSED AND THE ELEMENTS OF A MAJOR GEOGRAPHIC BASE FILE ARE IDENTIFIED. THE BENEFITS OF A NATIONWIDE SYSTEM ARE DISCUSSED, INCLUDING; (1) REDUCTION IN DESIGN DUPLICATION, (2) REDUCTION IN COSTS OF DEVELOPMENT, (3) MORE EFFICIENT USE OF STATISTICS, AND (4) INCREASED COMPATIBILITY OF MULTI-AGENCY DATA. IMPLEMENTATION POLICIES AND SUCCESSES ARE ADDRESSED, AND THE TRANSFERABILITY OF PACKAGES TO A SIMILAR PROGRAM IN OTHER NATIONS IS NOTED. (KBL)