This paper argues for explicit consideration of data fidelity during development of context-aware systems. Increasing the amount of data captured, stored, and distributed does not always translate into into increased fidelity, and we can leverage this to avoid unnecessary energy overhead and increase device battery life. We introduce Context-Awareness Fidelity Expression (CAFE) as a framework for deliberately specifying application data fidelity adaptation with the aim of using context-awareness to reduce energy consumption.