The returns on continuing vocational training (CVT) in enterprises were examined through a review of research on the returns on employer-provided training. A search of "Econ Lit," ERIC, and other databases identified more than 90 publications on the topic. Twenty-one publications examining the relationship between training inputs and training outputs from a variety of perspectives were selected for in-depth analysis. The following were among the review's main conclusions: strict rates of return have rarely been calculated; training is shown to have positive effects on wages and productivity; evidence suggests that training received from one employer increases productivity and wages with another employer; and selection effects matter in training. The studies were also analyzed from the standpoint of the issues involved in measuring the returns to CVT investments. The amount of empirical research concerned with estimating returns to CVT was discovered to be relatively sparse and underdeveloped. It was recommended that more thought be given to methodological issues, such as the suitability of qualitative and quantitative research and whether they can complement one another. (The 21 studies are summarized in an annotated bibliography. The document contains 93 references.) (MN)