Ongoing evaluation of student progress is a key practice within tiered systems of supports. This study evaluated whether selecting an intervention influenced the number of observations participants requested before determining whether an intervention was working or a change was needed. It was hypothesized that participants who selected the hypothetical intervention would request more data points relative to participants that did not choose the intervention when students were not showing adequate progress, consistent with the sunk-cost fallacy. Whether or not participants chose the intervention had no effect on the number of observations requested before a decision was made, on average. However, participants that selected the intervention were less accurate regarding whether a change did or did not need to be made. Implications for problem-solving teams evaluating student response to instruction as well as ideas for future research exploring cognitive biases on decision-making in problem-solving frameworks are offered.