The LSI is one part of the assessment and evaluation system under development in Ontario probation and parole. Fifty-eight items in the LSI are grouped under the major categories of criminal history, education and employment, financial, family, accommodation, leisure and recreation, companions, alcohol and drug problems, emotional and personal, probation conditions, and attitudes and orientation. During the summer of 1980, Ottawa officers began to use the LSI routinely. The first 598 LSI's completed, coded, and stored in the research files constituted the primary validation sample for this report. LSI scores predicted all of the following above chance levels: officer judgments of appropriate levels of supervision at intake, officer judgments of appropriate levels of supervision while in progress, officer judgments of the success of supervision, actual amount of supervision activity as reflected in casebook entries, early terminations versus regular terminations, early closures versus active supervision, any evidence of inprogram recidivism, multiple reconvictions, incarceration, and officially undetected self-reported criminal activity. The approach taken emphasizes the value of LSI as a decision aid. The LSI format has a built-in flexibility which encourages its refinement as experience warrants. The appendix contains some item-by-item analyses of the LSI, and tabular data and 14 footnotes are provided.