The concept of school is widely used in attempts to understand the history and contemporary structure of sociology. For the most part it is used informally, without definition, to refer to groups of sociologists assumed to be sharing a certain perspective and perhaps a particular institutional location. This casual approach to the term has lead to a plethora of different concepts trading under the same label. This has tended to handicap, rather than help, those sociologists and historians of the social sciences who have attempted a more rigorous analysis using the concept of 'school' as a metascientific category. 
The casual approach to the term school involves nothing much more than a process of grouping together practitioners into convenient pigeon-holes in order to boundary, and thus facilitate, a sociological or historiographical analysis. The nature of a 'school', when the term is used in this casual way is determined by the structure of the pigeon holes, rather than by any explicit thesis about, either, the internal structuring of a research unit, or of any thesis about the nature of scientific knowledge and its development.
The term 'school', when appropriated in this rather informal way, has been used to group people together to show similarities in style, approach, epistemology, theoretical concerns, or substantive interests. Such groupings may be restricted to people working in the same place at the same time (e.g. The Centre for Contemporary Cultural Studies). Alternatively, 'school' might refer to a number of 'generations' of practitioners bounded by a particular institutional affiliation (such as the Frankfurt School) or 'allegiance' to a recognised central figure (such as the Durkheimian School and the Parsonian School). Or, a 'school' may be used to refer to contemporaries scattered across a number of institutions but who are seen as having some sort of identifiable common core (e.g. the structural functionalists). A wider meaning still occurs where the core is seen to span a period of time and space such that members could not possibly have worked either together, or in the same environment, but have been identified as having adopted some tenets that stand independently of the research situation. This last is usually referred to as a 'school of thought' (e.g. Marxism, or Pragmatism). 'School' has also been used in conjunction with groupings of people circumscribed by national boundaries (e.g. Polish School of Sociology; Soviet Sociology; The French School of Sociology) .
However, there have been attempts to develop the idea of 'school' and make it into a more rigorous metascientific concept. Approaches that use the 'school' as some form of metascientific unit prescribe the nature of the school in explicit terms that are informed by both the internal structure and dynamic of the social unit and by a thesis about the nature of the growth of social scientific knowledge (Mullins, 1973; Radnitzky, 1973; Tiryakian, 1979a; Besnard, 1983; Bulmer, 1984a). The development of this more rigorous metascientific concept of school owes a lot to the debate in the philosophy of science, in particular to Kuhn's (1962, 1970) 'paradigm' thesis and to Lakatos' (1970, 1975) 'methodology of scientific research programmes' (see Harvey, 1985, 1986).
The result has been a number of related, but distinct, ideas as to what constitutes a viable metascientific unit. These range from 'invisible colleges' (Price, 1963, 1965; Crane, 1972) through 'networks' (Mullins, 1973) to 'schools' (Tiryakian, 1979a, 1979b; Bulmer, 1984, 1984a). While substantial differences exist between these various metascientific units they have certain elements in common. Although differing in scope, they are all closely defined concepts and they each prescribe the criteria for demarcation of any co-operating group as a metascientific unit. All see research units as integrally related to the development of science and all delimit their respective metascientific unit to a group of communicating researchers.
The metascientific construct of 'school' is the narrowest of these units and tends to refer only to people who work in a closely defined institutional context and/or in close association with a dominant leader figure. Metascientific schools have thus been likened to 'schools of art' with a charismatic leader by those who adopt the concept , while those less sympathetic see schools as insular, rather like religious sects (Krantz, 1971a; Crane, 1972; Lakatos, 1975).
While not everyone agrees as to the exact nature of 'schools', Tiryakian's (1979a) model has proved popular among sociologists and historians of sociology. His is a rather rigid model, however, and Bulmer (1984a) has developed it into a more flexible construct (Harvey, 1986). Bulmer suggests that a number of features are likely to be present in some form if the social grouping can be said to be a 'school'. A 'school' has a central figure around whom the group is located, who is an inspiring and effective leader, whose school it essentially is and without whom the school begins to break up. The school needs an infrastructure that includes a propitious academic and geographic location, institutionalised links with existing bodies, external financial support and a means of disseminating its work. A school must attract students and develop an intellectual attitude and be open to ideas and provide a climate for 'intellectual exchanges between the leader and other members of the group'. A school is thus a more closely-knit group 'than is usual in academic departments or disciplines' (Bulmer, 1985,p. 67) .
 The usage of the term metascience reflects that outlined by Radnitzky (1973). It is research into science as a developer of knowledge. Etymologically, it is something coming 'after' science, or 'about' science. Science is here taken to refer to any empirically grounded area of enquiry, through which theoretical statements about the nature of the world (physical, natural or social) are made. This position is synonymous with such terms as 'Wissenschaft', 'scienza' and 'nauka'. Return
 Szacki (1975) suggests that schools are also construed by reference to substantive content of a research area. Return
 Tiryakian (1979a) referred to the surrealists around Breton and Bulmer (1984a) referred to the Bauhaus School and the Impressionists. Besnard (1983) also likens sociological schools to schools of art. Return
 Both Tiryakian's and Bulmer's criteria for schools are the result of an inductivist generalisation from a few cases. Return
Next 1.3 Constructions of the 'Chicago School'