Problem-based learning currently refers to a wide variety of practices underpinned by different ideologies and purposes.  The literature reflects this diversity which brings with it both confusions and concerns about how problem-based learning might be understood.  The majority of the literature in the late 1970s and 1980s argued for the use of problem-based learning (including, and beyond, the original reasons suggested by Barrows and Tamblyn 1980) for three key reasons.
 

Three key reasons
The first reason was that of developing ‘skills’, and in particular reasoning skills.  Little and Ryan (1988); Loewenthal (1986); Prosser (1985), and Van Langenberghe (1988) all include within their problem-based programmes the development of skills particular to the profession, or in the case of Titchen (1987a) the continuing development of ‘professional skills’ in post registration education.  Furthermore Olson (1987) and Shahabudin (1987)
suggest that clinical reasoning skills are obtained through problem-based learning, and that through problem-based learning the development of these skills is made more explicit to the students.  The second reason was that learning should take place within a context which is relevant to the students and is attuned to the world of work.  Little and Ryan (1988) suggest
problem-based learning is used to provide a learning environment which ‘reflects the action-based nature of the profession’.

Shahabudin (1987) introduced problem-based learning to help students understand medical sciences in the context of a problem scenario. Loewenthal (1986) used it to enable students to explore and define problems in the context of their own experience and that of their organization, and then to consider how concepts from academic disciplines related to these. The final reason was the promotion of self-directed learning, that is, learning which fosters independent inquiry.  Problem-based learning is said to enable students to become self-directed learners, so that they know how and what to learn, and are thus equipped as life-long learners, and are better able to cope with the rapidly changing world.  (Hurley and Dare, 1985; Maitland, 1985; Loewenthal, 1986; Titchen, 1987b; Van Langenberghe, 1988).
 

A number of articles cite lists of advantages of PBL over more traditional ways of learning (Loewenthal, 1985; Neame, 1982; Coles, 1985) and others suggest that PBL is found to be more enjoyable and stimulating by staff and students involved in programmes which use PBL (Olson, 1987; Neame, 1982).  However, few seem to tackle many of the underlying assumptions of PBL or relate them to current trends in the broader context of changes within
professional education.
 

In recent years there has been a move away from literature which describes PBL, and how it is working in particular courses, towards critical analyses of PBL which are more sensitive to the complexities of this approach to learning and teaching (for example Margetson, 1991a; 1991b; 1993a; 1993b; 1994). This demonstrates the increasing shift from what Boud and Feletti (1991) term a ‘decade of evangelism’ in the 1980s  towards a deeper consideration of the emerging themes and issues.

PBL is an approach which requires students to use skills and life experience in order to utilise the knowledge they have gained.  Many suggest that PBL has implicit within it the idea of reflection.  This is because it appears to be an approach which requires students to use skills and life experience in order to utilize the knowledge they have gained, and to reflect upon
these processes.  Andersen (Andersen, B. 1990 Problem-based Learning in Nursing Education. Justified or a Response to Fashion?  Paper presented to Department of Medical Education, School of Medicine, Southern Illinois University. USA) includes this as a specific component of the nursing programme as do Heycox and Bolzan (1991). Yet little is discussed
in the literature about the quality of students’ experiences (for example Coles, 1991; Bawden, 1991; Engel, 1991) or about how reflection occurs in reality within problem-based programmes.

The development of reasoning skills is still said to be furthered through PBL.  Andersen (Andersen, B. 1990  Problem-based Learning in Nursing Education. Justified or a Response to Fashion?  Paper presented to Department of Medical Education, School of Medicine, Southern Illinois University. USA),  Yang (1991) and VanLeit (1995) suggest that clinical reasoning skills are gained through PBL and that through this method of learning the
development of these skills is made more explicit to the students.  In terms of research there still appears to be little evidence to demonstrate that this is so. The development of skills has become increasingly important as higher education in the 1990s is being encouraged to move towards developing students’ knowledge and abilities which are both flexible and market
related.  (Bridges, 1993; Barnett, 1994).  A number of authors (Van Berkel, 1990; Blosser and Jones, 1991; Des Marchais et al, 1992; De Virgilio, 1993) see the development of skills as the underlying purpose of implementing PBL.  It may be that the development of these skills is also included in traditional curricula.  However it would seem that PBL is increasingly used as a vehicle to develop skills for life and work in the continuing move away from liberal education, that is the kind of education which was perceived as ‘a cultural or positional good’ (Barnett, 1994 : 4).  This is occurring at a time when students are being asked not only to make choices intellectually but also pursue these choices practically by acting in and upon a
competitive social world (Bridges, 1993).
 

Current trends
Literature has also emerged over the last six years which is beginning to explore in depth both the nature of PBL, its underlying theoretical tenets and its political implications.  Margetson (1991a; 1991b; 1993a; 1993b;1994) discusses the complexity of the issues surrounding PBL in relation to institutions, political systems, different cultures and economic climates and considers the challenge of implementing PBL. The importance of this more recent literature is in its discussion about the underlying assumption of PBL, and the conceptions of language, knowledge, expertise and facilitation which are seen to be implicit within it as a method of learning.  Furthermore the body of research into PBL has become more substantive in the last 10 to 15 years. For example research since its emergence in the sixties has been relatively limited and much of the literature has been anecdotal in nature.  Studies which have been carried out have been predominantly in the field of evaluation due probably to the increasing demand by institutions and State to evaluate courses in higher education.

Research has largely stemmed from the desire of those who have implemented PBL into courses to ascertain the effectiveness of this implementation (see for example Vernon and Blake, 1993)  Other research documented includes comparative studies, either between traditional and PBL programmes, or between staffs’ and students’ differing perspectives of particular issues within PBL curricula.  Research has also been carried out into concerns
which have emerged through implementation of PBL programmes, namely assessment and staff and student experiences of PBL.