Mitigating frustration is important within computer-based learning contexts. In this experimental study where participants were purposefully frustrated, the interface agent message (apologetic, empathetic, or silent) was manipulated to investigate its impact on student attitude toward the task, attitude toward the agent, and attribution toward the cause of frustration. Fifty-seven undergraduate students responded to an invitation to participate in a web-based survey and to receive a movie ticket for their effort. An animated interface agent, “Survey Sam,” was present as students answered survey items and were confronted with a frustrating obstacle – an error message pop-up window that blocked them from answering the survey items. Survey Sam delivered either an affective message (apologetic or empathetic) or remained silent to the thirty students who actually completed the survey. Results revealed that the presence of an affective message (either apologetic or empathetic) led participants to report significantly greater frustration, suggesting that the affective message reinforced and validated their frustration. However, and more importantly, they attributed the cause of their frustration to the program instead of to themselves (as did the no message group). A comparison of message type (apologetic or empathetic) indicated that participants receiving the empathetic message rated Survey Sam as significantly more believable and sincere. Implications of these findings as a catalyst for further research in the development of frustration-mitigating support for computer-based contexts are discussed.