The second article in this series on the history of evaluation use has three sections. The first and longest develops a functional definition of the term "use," noting that a thorough definition of evaluation use includes the initial stimulus (i.e., evaluation findings or process), the user, the way people use the information, the aspect of the program considered, and the purpose. It then defines evaluation use's unethical companion, misuse, detailing the distinction between the two. The second section briefly discusses a broadened concept of evaluation impact that expands to include evaluation influence. Finally, the third section summarizes the factors that research has shown to be related to evaluation use.