The goal of ASENT is to construct solid conceptual and methodological foundations for the science of animal sentience. The term sentience refers to an animal’s subjective experience of the world and of its own body. In recent years, an interdisciplinary community of animal sentience researchers, drawn from neuroscience, comparative psychology, evolutionary biology, animal welfare science and philosophy, has begun to emerge. However, the field is characterized by foundational controversy over the nature of sentience and the criteria for its attribution, leading to heated debate over the presence or absence of sentience in fish and in invertebrates such as cephalopods and arthropods. ASENT aims to find ways to resolve these debates, enabling researchers to move beyond the impasses that result from deep foundational disagreement. What is needed is a conceptual framework for thinking about sentience as an evolved phenomenon that varies along several dimensions, a deeper understanding of how these dimensions of sentience relate to measurable aspects of animal behaviour and the nervous system, and a richer picture of the links between sentience, welfare and the ethical status of animals. ASENT will answer this need by providing: 1. An account of the basic functional capacities involved in sentience, and an evaluation of which capacities justify us in regarding an animal as a sentience candidate. 2. An overarching conceptual framework for understanding the dimensions along which sentience varies across the animal kingdom, based on distinguishing multiple structural properties of sentience; 3. A scheme of proposed experimental tests for constructing a species’ most likely sentience profile with reference to these dimensions, implemented with scientific collaborators using bees as a test case. 4. An assessment of which dimensions of sentience are most relevant to animal welfare and to the ethical status of animals.