**2.3. Occupation**

In exploring occupational therapy (OT) and its role in the treatment of individuals with an ASD, time must be spent defining the term occupation. Historically, the term *occupation* was defined as the way in which people use or occupy their time [4]. Yerxa, one of the founders of occupational science, more recently defined occupation as the "specific chunks of activity within an ongoing stream of behavior which are named in the lexicon of the culture…. These daily pursuits are self-initiated, goal directed (purposeful) and socially sanctioned" ([5], p. 5). Other occupational therapy scholars have described occupation as everything people do to occupy themselves, including looking after themselves (self-care), enjoying life (leisure) and contributing to the social and economic fabric of their communities (productivity) [6].

Occupations occur throughout the lifespan, in context, and are influenced by the interplay among client factors (capacities characteristics and beliefs of the person), performance skills (goal directed actions), and performance patterns (habits, routines, and roles). Occupations occur over time; have purpose, meaning, and perceived utility to the individual; and can be observed by others (e.g. writing one's name) or known only to the person involved (e.g. morning grooming routine). Occupations can involve the execution of multiple activities for completion and result in various outcomes. The broad range of occupations are categorized by the American Occupational Therapy Association (AOTA) into activities of daily living (ADLs), rest and sleep, education, work, play, leisure, and social participation [1]. To understand how these occupational categories are used in therapy, it is important to review the occupational therapy philosophy.
