The carry-over effect in end user computer training refers to the transfer of a person's computer skills from one application to another. The importance of the carry-over effect is unquestionable, but its nature has not been well understood. In this article, a research agenda is developed to analyze the nature, the roles, and the antecedents of the carry-over effect. Three fundamental questions are asked: 1) what is the carry-over effect and how to measure it? 2) What roles does it play in end user computer training? And 3) what factors determine the carry-over effect? Propositions are developed to give directions in further empirical research, and some preliminary evidences are discussed. Potential implications for Information Systems research and practice are discussed.