Research methodology involved examination and comparison of changes in three of four courts (Chicago, Detroit, and Brooklyn) whose sentencing councils had been operating for some time. The period examined encompassed the late 1950's and 1960 's. Historical study, interviews and observation, study of court records, construction of a theoretical framework, and hypothesis testing through quantitative time-series analysis and comparative case analysis characterized the research effort. The method of analysis used to examine the councils' effectiveness had several components: developing a measurable concept of sentencing disparity, collecting data, specifying the kinds of changes expected, specifying a strategy for analysis of the effects of sentencing councils, and developing a set of criteria for identifying sentencing council impact. Findings revealed that the effect of introducing a sentencing council into a court cannot be predicted without knowledge of many court characteristics, so no conclusion can be made about the general usefulness of the councils in reducing disparity. Sentencing councils were shown to reduce or increase sentencing disparity, depending upon the other variables involved. In addition, it was concluded that sentencing councils can polarize sentencing attitudes. Footnotes, one figure, and two tables are provided.