This research follows on a previous study that investigated how digitally augmented devices and knowledge building could enhance learning in a science museum. In this study, we were interested in understanding which combination of scaffolds could be used in conjunction with the unique characteristics of informal participation to increase conceptual and cognitive outcomes. Three hundred seven students from nine middle schools participated in the study. Six scaffolds were used in various combinations. The first was the digital augmentation. The next five were adaptations of knowledge-building scaffolds. Results demonstrated that digital augmentations, posted questions, and participation in collaborative groups may be the optimal design for improving conceptual learning (content knowledge) while preserving informal participation behaviors. However, our results also showed that obtaining deeper cognitive gains such as ability to theorize only occurred in the most highly scaffolded condition in which students demonstrated much decreased informal participation behaviors. We discuss the implications of our results with respect to the broader research on improving learning in informal science learning environments.