The study found a 15-percent increase in California's probation population since 1975 and a 20-percent decrease in the number of probation officers. In the same time period, the State spent 30 percent more on criminal justice in general, but 10 percent less on probation. Results are reported for analyses of data for over 16,000 felons convicted in California's superior court during 1980 and of recidivism data on a subsample of 1,673 who received probation. Felony probation is shown to present a serious threat to public safety; only 35 percent of the probationers managed to 'stay clean.' With the exception of drug offenders, the study found that probationers were most often rearrested and convicted of the same crimes charged in their initial convictions. Additionally, property offenders tended to be rearrested more quickly than those originally convicted of violent crimes or drug offenses. Regression analysis identified the following factors as most significantly related to recidivism: type of conviction crime, number of prior convictions, income at arrest, and household composition. The use of information gleaned from presentence investigations was found not to be of use in improving the recidivism prediction. Finally, the use of intensive surveillance programs in lieu of probation for felony offenders is considered. Six figures and three references are included.