This study attempted to test the predictive utility of two competing theoretical arguments present in the job commitment literature. The first argument, called the ''structural" approach, maintains that commitment is best explained by structural traits of workers. Such traits refer to objective characteristics of individuals and include, for example, the educational level of workers, their occupational length of service, and age. The second argument, labeled the "attitudinal'' approach, claims that various subjective characteristics of workers best account for commitment. Such attitudes include, for example, employees' perceptions of their satisfaction and role conflict within their jobs. Variables representing each theoretical argument, as well as scales measuring occupational and organizational commitment were used in a 1975 survey of a sample of park and forest rangers working in the state of Virginia. In 1980, follow-up data were collected from the original sample. Difference of mean tests, zero-order correlation, multiple correlation, and multiple regression were used in the data analysis. The results of this study show that both occupational and organizational commitment significantly declined among the rangers surveyed from 1975 to 1980. During the time period of the study, the structural variables accounted for a greater percentage of the variance explained in both occupational and organizational commitment. Implications for the two theoretical arguments are discussed.Ph. D.