Through this study the authors evaluate outcomes associated with the use of handheld computers by interventionists in improving the efficiency of direct systematic classroom observation. Information from observations is used by interventionists for treatment planning and evaluation. In this study, interventionists were trained to use personal digital assistants with classroom observational software for use with students who displayed low levels of academic engagement. Results indicated that the personal digital assistants and observational software were perceived as user-friendly, increased computer self-efficacy, and facilitated treatment planning and evaluation. Discussion focuses on implications for use of handheld computers and mobile devices by interventionists. (Contains 2 tables.)