Case Study

  1. Descriptive Case Study
  2. Explanatory Case Study
  3. Case Study As A Basis Of Forecasting
  4. From Case Studies Towards General Theory

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Case study, sometimes called monograph, means studying only one event, process, person, organization unit or object. Such an approach would not seem to promote the general target of research - to unearth generally valid knowledge - but it can be motivated for various reasons, typically the following:

Case study Among the alternatives above, only C and D are able to produce generally valid knowledge. Types A and B only aim at describing a case, and they do not search universally valid knowledge. Nevertheless, it is always possible that some findings of a case study can also later be applicable to other cases which have not been studied, though this is usually difficult or impossible to assess in the framework of a single case study. In any case, anybody later reading the report of a case study can himself evaluate which findings he perhaps can apply to his own problems (figure on the right). The entire process of study and application thus resembles creating and enjoying a work of art, discussed on the page Art as Analysis.

What kind of knowledge you can expect to find with a case study? In the diagram above, the findings are characterized as 'description', but also other types of knowledge can be obtained with case studies. Usual targets in case studies are:

  1. Describing the object or phenomenon - not only its external appearance but also its internal structure, and perhaps also its earlier phases of development.
  2. Explaining the reasons why the object is as it is, or its earlier development.
  3. Predicting the future of the object.
  4. Planning improvements to the object or to other similar objects, or gathering opinions about it, in other words a normative approach.

The above mentioned targets and their respective methods will be discussed below, excepting the normative approach, the methods of which differ radically from the rest. It is therefore discussed on separate pages: Normative Point of View, Normative Case Study and elsewhere.

Descriptive Case Study

When planning an empirical study it is usually advisable to base the work on an existing theoretical model, because a model, even a preliminary one, can often help the work decisively. Not basing the study on any earlier model or theory is usually laborious, slow and uncertain, so usually you will want to avoid such an exploratory approach if you can. Accordingly a new case study is normally started with a search of literature for information and potential theoretical models.

On the other hand, sometimes there can be reasons for not basing the study on any model or theory, even when there is one. Reasons for this could be, among others:

Selecting an exploratory approach, i.e. using no theoretical basis, for a descriptive case study can thus be either a deliberate decision, or a necessity because no suitable theory or model is available. In either case, exploratory research means that at the outset of the project hardly anything is known about the matter. You will have to begin with a rather vague impression of what you should study, and it is also impossible to make a detailed work plan in advance nor to define the concepts of study. You have to start with a preliminary notion of your object of study, and of its context. During the exploratory research project, these provisional concepts then gradually gain precision.

In the absence of tried models and definite concepts you must start the exploratory study from what you have: the object of study. It is common that in the beginning of an exploratory study you will look at the object as a holistic entity, and regard all its attributes simultaneously. You do not want to restrict your study to just a few characteristics of the object, before you know which questions are important. You thus start by gathering as much information about the objects as possible, and postpone the task of cutting away unnecessary data until you get a better picture about what is necessary.

ViewpointsAny object can be looked at from several different viewpoints, or as belonging to different contexts, and it can often be a good idea to start the study by alternating the point of view, like in the diagram on the right.

After you have spent a few days in experimenting with various vantage points to the object, you will probably be able to specify the final point of view for your study and explain how you understand or "take" the object. You need not necessarily start your work by clarifying the essence of your object of study, i.e. what the object really is, but you should contemplate and clarify how you see the object: for example, should it be defined on micro level as a result of the individuals' instincts, drives and experiences, or maybe on macro level as an expression of prevalent ideologies and pressures in society.

The progress of a project of study becomes easier as soon as you have defined your point of view and your problem. After this, you will need to gather only such empirical knowledge that is related to the problem; that will enable you to restrict the material you will have to analyse. This does not mean that you should disregard all the cases that do not fit into your conjectures, on the contrary - sometimes anomalies or surprising cases can point the way to important amendments or corrections to existing theory.

As soon as an interesting structure or invariance in the object becomes apparent you can omit all the material that has no relevance with this structure, and compress the remaining, relevant information.

It will seldom be possible to divide exploratory study into such clear phases as is common in the case that the object has been studied earlier. According to Alasuutari (1993 p.22), in qualitative analysis of empirical data, you can distinguish two phases but these two overlap:

In the simplification phase, the material is inspected from the point of view of the theoretical structure that has been found, and only the points relevant from this angle are noted. Not relevant details are omitted or pushed aside so that the important structure can be discerned more easily. Sometimes the most interesting structures are those that can be expected to be common for all comparable cases - this aspect is discussed on the page Finding the Typical.

"Solving the enigma" does not always mean answering exactly those questions that were asked at the outset of the project. Sometimes the most interesting questions are found at the end of the project, when the researcher has become an expert on the subject.

Describing a Case on the Basis of Theory. Today, almost every conceivable topic has already been studied by one or more specific fields of research. Almost any arising question or potential object of case study can therefore now be investigated in the light of earlier theory.

In established fields of research you can often select your problem so that it allows handling your object as a special case or extension of existing theory, created by earlier researchers. Such a practice is, indeed, much used in academic science, because it facilitates launching a new study and carrying it out.

Besides, you can often combine the vantage points of two or more fields of science, which can reveal interesting new aspects to the topic, in the same way as a hermeneutic study of literature.

Viewpoints Using parallel vistas to a single object is logical and easy to organize in the case that several researchers cooperate in the project. Each researcher can then look at the object from the point of view of his special expertise, and the resulting views are then joined together by discussions in the team.

An explorative researcher working alone can instead use the method of alternating the point of view. This means that you study the object successively from several viewpoints, each of which is based on an existing theory, as in the figure on the right. Each vista enhances the general picture.

Explanatory Case Study

Often the researcher wishes to continue the project to a deeper level than a mere description: he wants to know why the object is such as it is. This knowledge helps summing up all that is known about the object, it helps to see it in its context and in a historical perspective.

Finding the reasons, or explaining the phenomenon, can be done in a number of ways where the reasons are fetched either from the concurrent context of the phenomenon, or from the past or alternatively from the future. In the following are examples of three types of explanation which are common in research as well as in everyday life.

Of these types, the contextual explanation is popular when studying the activities of man and its results, such as industrial products and works of art. These have long been studied in various sciences such as sociology, anthropology, economics and psychology, and it is normal to exploit theories of these sciences when the goal of a new research project is to find an explanation to the state of the object of study. Earlier theories about the relationships of comparable activities or products and their contexts can facilitate and speed up the procedure of a new research project in the same way as it does in descriptive case study, discussed in the preceding paragraph. When one or more theories for explanation are available, the logical approach is to try each of them as a working hypothesis, and then elaborate the explanation that seems most plausible.

Perhaps the most usual contextual explanation is a sociological one: "The designer is seen as a part of the surrounding society, and his work and values are examined in connection with social, cultural and economic conditions... We have to understand how and why design has evolved and whose interests it supports" (Wiberg, 1992).

Likewise, industrial products and works of art are often studied and explained on the basis of social, economic and ecological processes. Explaining factors are, for example, changes in society demographics, in industry or in economic conditions, inventions, education, political changes, wars, and the acquisition or loss of colonies. Constant but regionally dissimilar factors are climate, supply of raw materials and energy, channels of transport and the local needs of people.

ContextAn example is Päivi Hovi's study about pictures in advertisements in Finland from 1890 to 1930. She found that to understand the pictures you have to study them from four viewpoints or contexts which are illustrated in the diagram on the right. Each of these contexts had been the object of earlier studies and the accumulated knowledge and theory provided potential approaches for the study of the empirical material gathered by Hovi. Although strictly speaking this was no case study, the objects being actually not single objects but classes of them, the approach can quite well be used in a case study, too.

The psychological approach is usual in the study of artists and their works, as well. Especially Wilhelm Scherer's (1841 - 86) general model for the biographies of artists has been much used. It explains the special character of each artist by three factors:

Explanation by earlier events obviously calls for diachronic study, in other words you will need material from a longer period of time. The time span varies - in physics causally explainable chains of events often take place in less than a second, while the effects that various foods and their additives can cause to man can need many years to appear. In any case, widening the time span of the study necessarily expands the amount of material that you have to gather and analyze before the study can be finished. To prevent excessive growth you have to consider demarcating the extent of study more narrowly.

When deciding which material you will need to gather, an invaluable starting point could be earlier findings about which factors have been interrelated in earlier comparable objects. In the absence of such theories you have to find the causal explanation in the object itself. This would require gathering lots of material, studying it in historical perspective, and noting the various changes that now and then have occurred in or around the object. Next you should inspect closely these points of time and the events before and after them. Among these events you perhaps can find plausible explanations for the changes that have taken place, and finally for the present state of the object. Such an approach is discussed also in Explaining a Development.

Explanation by later events. The intentions of people can be gathered by interviewing, or from documents such as budgets, plans and proposals of officials, politicians, businessmen and artists, and memoirs of these people. Other sources are product concepts, specifications, proposals and documents from evaluation sessions.

A difficulty when trying to explain people's behavior on the basis of their announced intentions is that the later behavior of people does not always quite correlate with the expressed intentions, sometimes because of unforeseen practical obstacles encountered in the realization phase, and sometimes because the announced intention has not been realistic enough or honest. This problem is discussed on another page: Assessing the Information.

Case Study As A Basis Of Forecasting

When the purpose of a case study is to provide grounds for forecasting the future of the object or phenomenon, you should first of all define which characteristics of the future state of things are "interesting" and shall be included in the forecast. Obviously recent data about these are of primary importance as a basis for the forecast.

What other material is needed to make a forecast, depends on which method of forecasting you intend to use. This, in turn, depends on how strong a theoretical model you have about the expected future development and its internal relationships. { Quite a strong basis for forecasting is available when there is a model which explains the phenomenon, enumerating its reasons and their outcomes, in other words defining the dynamic invariance of the process to be predicted. Other, less reliable types of model that can be used in forecasting are statistical associations (e.g. correlations) between variables, and models or analogies borrowed from other contexts such as a distant sphere of culture.

A summary of possible methods of forecasting on the basis of a case study is given in the table that follows:

  Forecasting on weak or no theoretical basis: Forecasting on strong theoretical basis:
Required data: Data about the development of the "interesting" characteristics, from as long a period as possible Recent data about the "interesting" characteristics.
Besides, recent data on the supposed independent variables, according to theory.
Suitable methods of forecasting: Extrapolation ; Applying a Statistical Association ; the Delphi Method Several methods are possible. Especially reliable are Applying a Causal Model and Determining Limits.

From Case Studies Towards General Theory

The knowledge that a case can produce concerns the case that was studied, and at first sight it seems impossible to apply it to other cases or to a class of cases. Logically thinking it would seem that in order to get knowledge about a class we would need a research project which takes as its object the whole class, not only one case of it.

Generalizing case studiesAnother logical procedure for gaining generalizable knowledge could be combining the results from the study of several resembling cases or objects. If these separate case studies have unequivocal links between them, such as common definitions of concepts or structures of models, these will help later researchers to find recurring invariances which exist in the separate cases. In the best case these invariances can finally lead to constructing a general model which covers all the separate cases, or at least points out a typical case in the class (fig. on the right).

However, probably the most usual procedure for advancing from distinct case studies to generally valid knowledge is based on the fact that most case study researchers in reality have quite a lot of knowledge of other comparable cases already when they start their study. This generally valid knowledge then permeates their case study in the form of concepts, models and variables that relate with the other cases in the class. All this means that it becomes easier for other scientists - or laymen - to generalize the findings of this case study, if they want to try it on their own risk.

Improving earlier theoryToday, when there is so much published research about all thinkable fields of study, it is increasingly usual to base a new case study on the hypothesis that the case will behave in accord with an already existing theory. If it does, the area of validity of this theory will enlarge, and in the opposite case the researcher perhaps can modify this earlier theory. In both cases the results of the new study can be scientifically or practically valuable.

Another advantage of this approach is that it will usually greatly facilitate planning and carrying out a case study, as is explained elsewhere (Research on the Basis of Earlier Theory).

Normative Case Study is discussed on another page.

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August 3, 2007.
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Original location: http://www2.uiah.fi/projects/metodi