AN EXPERIMENTAL TRUANCY PATROL WAS SET UP IN BRISTOL, ENGLAND, A LOCALE JUDGED REPRESENTATIVE OF A MODERATELY URBANIZED REGION IN WHICH PATROLS HAVE RUN. THE STUDY COMPRISED TWO TIME-SERIES OBSERVATIONS, BEFORE AND AFTER HALF-TERM, SPRING 1978. IN EACH HALF OF THE TERM, OBSERVATIONS (COMPRISING VARIOUS DAILY COUNTS OF CHILDREN AT LARGE DURING SCHOOL HOURS) WERE TAKEN BEFORE, DURING, AND AFTER A WEEK'S PATROLLING, AND THESE WERE THEN CONSIDERED IN RELATION TO A NUMBER OF CRIME INDEXES. RESULTS SHOWED AN UNEXPECTEDLY LOW RATE OF DAYTIME OFFENDING BY TRUANTS. CLEARLY THE PATROLS MAY HAVE INFLUENCED THE BEHAVIOR OF SOME CHILDREN, YET THE STUDY DID NOT SHOW WHETHER THE SCHOOL ATTENDANCE OF THESE CHILDREN SUBSEQUENTLY IMPROVED OR WHETHER THE PATROLS CAUSED ANY OTHER CHILDREN TO RETURN TO SCHOOL OR STAY AT HOME. THE LACK OF CLEAR EFFECT OF THE PATROL MAY BE DUE TO THE SMALL PERCENTAGE OF TRUANTS AT LARGE THAT WERE STOPPED. THERE WAS NO DIRECT EVIDENCE THAT CRIME WENT DOWN DURING OR AFTER THE PATROLLING PERIOD. ACCORDINGLY, IT APPEARS THAT IMPROVING PATROL EFFECTIVENESS MAY REQUIRE MORE RESOURCES THAN MANY FORCES ARE WILLING OR ABLE TO PROVIDE. A WEEK'S PATROLLING DOES NOT APPEAR ADEQUATE. THE STUDY SHOWED THAT FOOT PATROLS MAY BE MORE EFFECTIVE IN CENTRAL SHOPPING AREAS AND CAR PATROLS IN THE SUBURBS. THE WEARING OF UNIFORMS ON PATROL APPEARED ADVANTAGEOUS. IN CONCLUSION, IT IS CLEAR THAT INCREASED PARENTAL COMMITMENT TO CHILDREN'S ATTENDANCE AT SCHOOL IS CALLED FOR. AN APPENDIX CONTAINS CORRECTIONS TO CHECKS ON THE CHILD COUNTS AND A LIST OF REFERENCES. (MJW)