A series of questions about how social processes are ordered, either temporally or spatially, together with the techniques for answering these.
Many areas of sociology are concerned with events or actions in their temporal context—or with what we might call sequence problems. The literatures on careers and the life-course are obvious examples. Sequence analysis seeks to determine the patterning of events (types of job shifts or whatever) in an ordered list or chain. Since there is no assumption of real time (as opposed to symbolic time), it is possible also to examine the successive parts of a ritual, or the order of steps in a manufacturing process (where the ‘time’ involved is in some sense artificial), as well as the sequencing of real-time events such as the changes of status involved in a work history or criminal career. Events in any sequence can be unique or can repeat and may have varying degrees of interdependence. Whole sequences may themselves be interrelated. Sequence can be investigated as an independent or dependent variable; for example, we may wish to know which sequence of job experiences best predicts unemployment, or which prior variables explain sequential steps in an occupational career. Some sequence analysis is interested merely in determining patterns in a series of events as an end in itself—as, for example, in the case of research into the ordering of steps in a dance.
This is a newly developing area in which sociologists are taking their lead mainly from the other social sciences. There is a long tradition of sequence analysis in psychology, in such areas as learning, cognition, and theories of developmental stages. Economists have studied the sequences involved in (among other things) consumption behaviour and the emergence of innovations. Linguists often explore the steps involved in constructing meaningful text. Political science includes sequential studies of (for example) the process of federal budgetary decision-making.
In sociology, a simple conception of sequential analysis occurs in the linear stage theories of modernization, development, rationalization, revolution, and so forth, associated with the names of Karl Marx, Robert Michels, Robert Redfield, and others. More sophisticated are the various career theories, such as those to be found in the literature on work histories, since these allow for more contingency and accident than do stage theories. The most developed forms of sequence analysis permit all sequences to be interdependent in a complex network. Andrew Abbott, one of the leading proponents of sequence analysis in sociology, refers to these as ‘interactional field theories’, and claims that they are rooted in the ‘contextualist paradigm’ developed by the Chicago School between the First World War and the 1930s. Examples would include Harrison White's network analysis of the vacancy chain system in labour markets (Chains of Opportunity, 1970) and Abbott's own study of the careers of German musicians during the 17th and 18th centuries (‘Measuring Resemblance in Sequence Data’, American Journal of Sociology, 1990).
Techniques for coding sequences, together with the associated computer software for analysing these, tend to be borrowed and adapted from existing applications in biology, cognitive psychology, and related fields. There are many such programs available, and since developments in this area are being funded mainly by biotechnology money, advances tend to be rapid. One such method, much used and refined by Abbott himself, is that of so-called optimal matching or optimal alignment. This computes a distance between any pair of sequences, based on the minimum number of replacements and insertions that would be required to transform one sequence into another. (The technique is borrowed from biology, where it has been used to investigate the resemblance of DNA molecules, and to construct trees of descent among them.)