Science educators increasingly call for students to address authentic scientific problems in science class. One form of authentic science problem--socioscientific issue--requires that students engage in complex reasoning by considering both scientific and social implications of problems. Computer-based scaffolding can support this process by giving students structure but also helping them focus on important problem elements. In this multiple case study from the ethnomethodological framework, we investigated how 7th-grade students from five small groups worked together to evaluate the credibility of evidence, make sense of data and evidence, and address a problem related to water quality in their local river. Data sources included video of students engaging in the unit, prompted interviews, database information, log data, and documents collected from computers. Results indicated that overall, the experimental small groups demonstrated more sophisticated epistemic beliefs and a more effective approach to solving the problem than the control small groups.