a national certification examination. Theoretical frameworks A distinguishing facet of occupational therapy is that therapists often espouse the use theoretical frameworks to frame their practice. Many have argued that the use of theory complicates everyday clinical care and is not necessary to provide patient-driven care. Note that terminology differs between scholars. An incomplete list of theoretical bases for framing a human and their occupations include the following: Generic models Generic models are the overarching title given to a collation of compatible knowledge, research and theories that form conceptual practice. More generally they are defined as "those aspects which influence our perceptions, decisions and practice". The Person Environment Occupation Performance model (PEOP) was originally published in 1991 (Charles Christiansen & M. Carolyn Baum) and describes an individual's performance based on four elements including: environment, person, performance and occupation. The model focuses on the interplay of these components and how this interaction works to inhibit or promote successful engagement in occupation. Occupation-focused practice models Occupational Therapy Intervention Process Model (OTIPM) (Anne Fisher and others) Occupational Performance Process Model (OPPM) Model of Human Occupation (MOHO) (Gary Kielhofner and others) MOHO was first published in 1980. It explains how people select, organise and undertake occupations within their environment. The model is supported with evidence generated over thirty years and has been successfully applied throughout the world. Canadian Model of Occupational Performance and Engagement (CMOP-E) Occupational Performances Model – Australia (OPM-A) (Chris Chapparo & Judy Ranka) The OPM(A) was conceptualized in 1986 with its current form launched in 2006. The OPM(A) illustrates the complexity of occupational performance, the scope of occupational therapy practice, and provides a framework for occupational therapy education. Kawa (River) Model (Michael Iwama) Biopsychosocial models Engel's biopsychosocial model takes into account how disease and illness can be impacted by social, environmental, psychological and body functions. The biopsychosocial model is unique in that it takes the client's subjective experience and the client-provider relationship as factors to wellness. This model also factors in cultural diversity as many countries have different societal norms and beliefs. This is a multifactorial and multi-dimensional model to understand not only the cause of disease but also a person-centered approach that the provider has more of a participatory and reflective role. Other models which incorporate biology (body and brain), psychology (mind), and social (relational, attachment) elements influencing human health include interpersonal neurobiology (IPNB), polyvagal theory (PVT), and the dynamic-maturational model