Summarizing a half century of work on the problem of identifying units of analysis for complex human behaviour, this book introduces modes of practice as a unit of analysis for the science and design of human activities, and shows how to record them and create field guides at scales from individual to society. Revealing scientific analysis of human practices has been hampered by the lack of a unit of analysis, Dirlam describes how the difficulties of defining a unit are overcome by combining insights from mathematics and human development. Part II presents methods for developmental surveys...