Hybrid lay-scientific concepts either arise outside the science domain and are later accepted by it, or have a scientific origin and are adopted by the policy domain. Typical examples are desertification, sustainable management, biodiversity and ecosystem services. They often evolve by accumulating multiple features in a piecemeal and unstructured way, and this contributes to uncertainty about them. Sustainability scientists could make such concepts easier to measure, and reduce uncertainty, by focusing on quantifiable state attributes — instead of all their features — and structuring attributes in more integrated ways.