It is difficult to come up with ‘answers’ in healthcare, and all the more so in professions such as occupational therapy that have inherently broad aims. However, it is known that professionals’ individual perspectives are highly vulnerable to a range of biases and heuristics when making clinical judgements (Gilovich et al 2002), regardless of their clinical ‘expertise’. It is also true that experience and ‘time served’ as a practitioner are fairly consistently shown to have no effect on improving clinical judgements (Grove and Meehl, 1996 and Grove et al., 2000). Knowledge of such inherent limitations of individual perspectives supports the acceptance and development of evidence-based decision-making approaches to therapeutic interventions. Frames of reference and conceptual models of practice are an ideal way in which clinicians can use theory, in a structured manner, to conceptualize clients’ difficulties, shape intervention and evaluate success. Using a well-developed frame of reference and/or conceptual model of practice encourages therapists to consider a whole range of options that they would perhaps be less likely to do if left to their own devices.

In her review of the history of occupational therapy in the UK, Wilcock (2001) attributes the first use of the terms ‘frame of reference’ and ‘model’ to Miss McLean, an American occupational therapist working as a lecturer in England (McClean 1974). McClean’s rationale for the development of a structured theory to underpin occupational therapy practice was financial. Hospital management, McClean (1974) argued, was no longer willing to tolerate therapeutic interventions for reasons of enjoyment alone. The requirement to demonstrate the value of practice had dawned and the development of theories, McClean suggested, would enable the evaluation of practice and research to be undertaken (McClean 1974). In today’s world of clinical governance and evidence-based practice, finance remains a dominant driver in the development of theory. It is certainly true, now more than ever, that the demonstration of effectiveness is of vital importance — not only for the good of the patients who receive the service, but also for the good of the profession as it faces increasingly probing questions about its worth in a financially challenging climate.

Structured theories develop out of a desire to explain the function and mechanisms of impact of occupational therapy, and help explain why a person is experiencing a particular problem, what a potential solution could be and why a particular intervention works. Structured theories provide explanations and describe the relationship between different aspects of a person (Kielhofner 2009). Theories also identify occupational therapy’s unique contribution to health and assist in defining professional boundaries (Feaver & Creek 1993b).

Supporting the use of structured theory in practice does not negate the requirements for occupational therapists to use their judgement. Occupational therapists have to decide which conceptual model provides the best evidence base and supporting structure for the setting in which they work. Sometimes this will be self-evident; it is highly unlikely that a psychodynamic frame of reference would be a useful primary frame of reference in an orthopaedic ward; the occupational therapist is more likely to use a biomechanical frame of reference and an associated conceptual model of practice. At other times, however, the case may not be so clear and a careful appraisal of the available evidence is required to inform theoretical decisions and the directions of practice.

Having articulated the rationale for having a structured theoretical basis for practice, we must now examine the importance of developing a clear understanding of the key terms that are used to articulate them. This is not straightforward as ‘different writers use them [theoretical terms] in different ways and their meaning is modified by the context in which they are used’ (Feaver & Creek 1993a, p.4).

The description of occupational therapy theory rapidly evolved from the mid-1980s on. Contemporaneously, the language that described theory developed and terms such as paradigm, model, frame of reference and approach were often used interchangeably and with different meanings by various authors (e.g. Creek, 1992, Hopkins and Smith, 1993, Kielhofner, 1992, Mosey, 1986, Reed, 1984 and Young and Quinn, 1992). Such variation adds considerably to the confusion of clinicians, students and academics who try to understand and evaluate contrasting conceptual foundations of practice. Hagedorn (2001) likened the struggle to understand the various uses of terminology in occupational therapy to the following discourse between Alice in Wonderland and Humpty Dumpty (Lewis Carroll, Alice Through the Looking Glass):

Whilst the debate about the ‘correct’ use of terminology appears to have abated, it is important to remain mindful that specific terms are still being used by different people in different ways. One solution to this is the development of internationally recognized standard definitions of theoretical terms and concepts. However, whilst this is a tempting proposal, it is questionable whether it could be meaningfully achieved. Differences in definitions of terminology are not simply semantic; they frequently expose an author’s conceptual bias. By way of example, two contemporary definitions of ‘models’, developed by theoretical leaders in the field, are provided here. Creek (2003, p. 55) defines a model as a ‘simplified representation of the structure and content of a phenomenon or system that describes or explains certain data or relationships and integrates elements of theory and practice’, whilst Forsyth and Kielhofner (2005, p. 91) highlight how ‘the strength and application of MOHO [a well-known conceptual model of practice] is neither simple nor formulaic. Instead it aims to understand important multiple dimensions of each client’s unique experience and bring a sophisticated understanding to bear on the life issues facing each client in practice’ (author’s emphasis added).

These contrasting contemporary definitions of models of practice illustrate: