The assessment of psychological situations in everyday life presents a number of methodological challenges, largely stemming from the need to assess situations as they occur in their natural context. Digital media devices (eg, smartphones, wearables, smart home appliances) that come equipped with a wide array of sensors address these challenges by making it possible to measure objective information about situations, many times, with great fidelity, over long periods of time, in a way that is both unobtrusive and ecologically valid. This chapter provides an overview of mobile sensing methods (MSMs) and describes how they can be used to capture objective information about situational cues (eg, social interactions, objects, activities, locations, time). It then describes opportunities for psychological research using MSMs to provide insights into everyday situational cues, characteristics, and classes. It concludes by discussing some of the practical considerations and challenges associated with using MSMs to assess situations.