This paper describes and contrasts findings from two related projects where groups of science pupils investigated local air pollution using a collection of mobile sensors and devices. Both projects however played out in different ways. A qualitative analysis of the projects points to the various issues that contributed to the different experiences despite similar technologies for a similar task. These include: project focus; type of facilitator input and the benefits of in-situ data collection combined with subsequent review and reflection. We point to specific relationships between technologies and context of use, and building on this draw out recommendations for the design of in-context, science learning sessions. This work contributes to the growing conceptual understanding, based on ‘real world’ experiences, of how mobile and ubiquitous technologies can be appropriated in context to support learning. It contributes to an increased understanding of the types of collaborative sci...