A study was made of 165 persons (largely underclass) during training at a job training center in middle Michigan and about one year later. Three kinds of influences were examined: opportunities, subculture, and training. Research was exploratory and involved comparison of 37 Chippewa trainees and 113 poor whites and a small number of Mexicans and Negroes. Procedures included interviews with trainees, observations, use of case records, a mailed employer's questionnaire, and interviews of a random sample of blue collar workers in the middle Michigan area. Four scales were developed to measure labor force mobility, opportunities, training and family background. The hypotheses examined provide support for the position that there is an interaction of the three types of influences, with there being a consistently greater association between opportunities and labor force mobility followed by the influence of job training and the still lesser degree of influence from the family dimension of subculture factors. The general conclusion is that opportunities of a level moderately above the trainees' pre-training experiences are most likely to motivate the members of the underclass studied when aided by comprehensive job training and positive family influences. (This thesis will be available from University Microfilms.) (EB)