The Case Study

Its limitations

1. Generalisation. The central objection: what is true of one unit need not be true of others, and a case study cannot establish how common anything is. A case study can show that something happens and can never show how often.
2. Selection bias. Cases are chosen because they are accessible, interesting or striking, which is precisely the way to choose an unrepresentative one.
3. Subjectivity. The researcher's interpretation is central and hard to check, and prolonged closeness to a single unit invites identification with it.
4. Not replicable. No other worker can study the same unit at the same time in the same condition.
5. Reliance on memory and self-report where the material is retrospective.
6. Time and cost, out of proportion to the number of units studied.
7. Ethical exposure. A single unit described in detail may be identifiable however carefully it is anonymised, which is a serious matter where the subject is a family, a small institution or a village.

How the generalisation problem is met

Not by pretending it does not exist. Four honest answers:

Analytic rather than statistical generalisation. A case study generalises to a theory, not to a population: it shows that a proposed mechanism does operate, which is a claim about how something can work rather than about how often it does.

Multiple case studies, selected deliberately to differ, so that what recurs across them is more likely to be general.

Combination with a survey, which is the practical answer: the case study finds the mechanism, the survey measures its incidence.

Deliberate selection. Choosing a typical case, or an extreme case, or a critical case, and stating which and why, so that the reader can judge what the case can support.

The case study and the survey

The clearest way to hold this is that they answer different questions and are complementary, not rivals.

The correct answer to "which is better" is that the question is wrong. A study of court delay needs the survey to establish how long matters take and the case study to establish how a particular matter came to take that long. Neither substitutes for the other.

Its use in socio-legal work

Worth naming, because it is where a law student will meet the method.

A single institution studied in depth: one legal aid clinic, one family court, one prison. A single community's experience of a legal change: a village after a land acquisition. A single process traced from beginning to end: one dispute followed from the incident to the final order, which reveals the delays, the costs and the decision points that no statistic shows. And life histories of litigants, of undertrials or of members of a profession.

The Law Commission's practice of illustrating a general problem with detailed instances, and judicial fact-finding through commissions of inquiry, are both close relatives of the method.

A worked example

A tenant's eviction proceeding, studied as a case.

Sources used: the case file and orders; interviews with the tenant, the landlord and both advocates; observation of hearings; the tenant's own account of the cost; and the court's registers.

What emerges that no survey could produce. That the matter was adjourned eleven times, of which three were at the court's own instance and are recorded in the file as being at the parties' request; that the tenant lost fourteen days of wages; that the decision to file a particular application was taken for reasons of delay and recorded as being on the merits; and that the parties reached an understanding outside the court which the record does not reflect at all.

What it cannot establish. Whether any of this is typical. It shows that these things happen, and a survey of five hundred matters would be needed to show how often, which is the division of labour set out above and the honest conclusion of the chapter.

Quick revision

1. Case study: intensive study of a single social unit as a whole, in its natural context, using all available sources. P. V. Young's definition.
2. It is not a case law study; the words coincide, the methods do not.
3. Characteristics: whole unit, intensive not extensive, natural context, all sources, mainly qualitative, a time dimension, very few units.
4. Merits: depth; the unit remains whole; it generates hypotheses; it reaches the rare and inaccessible; it shows process over time; a single case can falsify a universal claim; and it is flexible.
5. Limits: generalisation, selection bias, subjectivity, not replicable, reliance on memory, cost, and identifiability despite anonymisation.
6. Meeting the generalisation problem: generalise to theory not to a population; use multiple cases chosen to differ; combine with a survey; and select deliberately, stating whether the case is typical, extreme or critical.
7. Case study answers how and why; survey answers how many and how often. They are complementary.

Test yourself

1. Define the case study and state its characteristics. The intensive investigation of a single social unit, whether a person, family, institution, community or event, studied in depth and as a whole, in its natural context, using every available source of information. Its characteristics are that the unit is treated as a totality rather than dissolved into variables; that it is intensive rather than extensive; that the context is part of the data; that it draws on interviews, observation, documents and records together; that it is largely qualitative; and that it usually has a time dimension, tracing development.

2. State the merits of the case study. It reaches depth, detail, process and meaning that a survey cannot obtain, because a survey can ask only what was anticipated and must ask it of everyone alike. It keeps the unit whole, so the relations between its parts remain visible. It generates hypotheses for testing by other methods. It reaches phenomena too rare for a survey. It shows development over time. A single well-established case can falsify a universal proposition. And it is flexible enough to follow what emerges during the study.

3. What is the central limitation of the case study, and how is it met? That its findings cannot be generalised: what is true of one unit need not be true of others, and the method can never establish how common anything is. It is met by generalising to theory rather than to a population, showing that a mechanism can operate; by conducting several case studies deliberately chosen to differ, so that what recurs is more likely to be general; by combining the case study with a survey, so that one supplies the mechanism and the other its incidence; and by selecting the case deliberately as typical, extreme or critical and saying which.

4. Compare the case study with the survey. The case study examines one or a few units intensively, using qualitative material from all sources, treats the unit as a whole, and answers how and why something works, generalising only to theory. The survey examines many sampled units extensively, using a single standardised instrument, treats each unit as a set of variables, and answers how many and how often, generalising to the population if the sample is properly drawn. Their weaknesses are exact complements: one cannot say how common, the other cannot say how or why.

5. How is the case study used in socio-legal research? By studying a single institution in depth, such as one family court, legal aid clinic or prison; by studying one community's experience of a legal change, such as a village after land acquisition; by following a single dispute from the incident to the final order, which reveals delays, costs and decision points that no aggregate statistic shows; and by collecting life histories of litigants, undertrials or members of a profession. Commissions of inquiry and the Law Commission's practice of illustrating problems with detailed instances are close relatives of the method.