The difficulties inherent in determining sentence is highlighted in terms of the conflict between the several purposes of sentencing: punishment, protection of society, and rehabilitation. Also examined are the origin and extension of presentence investigations, the question of the public or confidential nature of presentence reports, the development of Federal probation from 1925 to 1950, and the nature and advantages of probation. Additional areas considered are the degree of success of probation, possibilities of improvement in the Federal Probation Service, and a new facility for the treatment of youthful offenders. It is concluded that Federal court judges are increasingly deciding that changing the attitudes of offenders through friendly probation supervision, combining firmness and sympathy, may be the most positive step toward rehabilitation. 31 footnotes.