Students' confidence in their responses to a multiple text-processing task and their justifications for those confidence ratings were investigated. Specifically, 215 undergraduates responded to two academic questions, differing by type (i.e., discrete and open-ended) and by domain (i.e., developmental psychology and astrophysics), using a digital library of seven varied texts (e.g., journal article, newspaper, Wikipedia). Students then indicated how confident they were in their responses and provided justifications for their level of confidence. This investigation had four main goals: (a) to determine the strength of students' response confidence; (b) to understand the criteria students use to derive their confidence ratings; (c) to consider the effect of task conditions on ratings and justifications; and (d) to examine the relation between students' response confidence ratings and justifications and the accuracy and quality of their responses. Students' justifications for response confidence were found to vary across task conditions. Further justifications for response confidence based on sources consulted (i.e., text-directed justifications) were found to relate to response accuracy for the discrete question and to response quality for the open-ended question.