Case Study

This section asks:

What is a case study?

There are many different text books and websites explaining the use of case studies and this section draws heavily on those of Lamar University and the NCBI (worked examples), as well as on the author’s own extensive research experience.

If you are monitoring/ evaluating a project, you may already have obtained general information about your target school, village, hospital or farming community. But the information you have is broad and imprecise. It may contain a lot of statistics but may not give you a feel for what is really going on in that village, school, hospital or farming community.

Case studies can provide this depth. They focus on a particular person, patient, village, group within a community or other sub-set of a wider group. They can be used to illustrate wider trends or to show that the case you are examining is broadly similar to other cases or really quite different.

In other words, a case study examines a person, place, event, phenomenon, or other type of subject of analysis in order to extrapolate key themes and results that help predict future trends, illuminate previously hidden issues that can be applied to practice, and/or provide a means for understanding an important research problem with greater clarity.

A case study paper usually examines a single subject of analysis, but case study papers can also be designed as a comparative investigation that shows relationships between two or among more than two subjects. The methods used to study a case can rest within a quantitative, qualitative, or a mixture of the two.

Image by mohamed Hassan from Pixabay

Different types of case study

There are many types of case study. Drawing on the work of Lamar University and the NCBI, some of the best-known types are set out below.

It is best not to worry too much about the nuances that differentiate types of case study. The key is to recognise that the case study is a detailed illustration of how your project or programme has worked or failed to work on an individual, hospital, school, target community or other group/ economic sector.

  • Explanatory case studies aim to answer ‘how’ or ’why’ questions with little control on behalf of researcher over occurrence of events. This type of case studies focus on phenomena within the contexts of real-life situations. Example: “An investigation into the reasons of the global financial and economic crisis of 2008 – 2010.”
  • Descriptive case studies aim to analyze the sequence of interpersonal events after a certain amount of time has passed. Studies in business research belonging to this category usually describe culture or sub-culture, and they attempt to discover the key phenomena. Example: Impact of increasing levels of funding for prosthetic limbs on the employment opportunities of amputees. A case study of the West Point community of Monrovia (Liberia).
  • Exploratory case studies aim to find answers to the questions of ‘what’ or ‘who’. Exploratory case study data collection method is often accompanied by additional data collection method(s) such as interviews, questionnaires, experiments etc. Example: “A study into differences of local community governance practices between a town in francophone Cameroon and a similar-sized town in anglophone Cameroon.”
  • Critical instance: This examines a single instance of unique interest, or serves as a critical test of an assertion about a programme, problem or strategy. The focus might be on the economic or human cost of a tsunami or volcanic eruption in a particular area.
  • Representative: This relates to case which is typical in nature and representative of other cases that you might examine. An example might be a mother, with a part-time job and four children, living in a community where this is the norm
  • Deviant: This refers to a case which is out of line with others. Deviant cases can be particularly interesting and often attract greater attention from analysts. A patient with immunity to a particular virus is worth studying as that study might provide clues to a possible cure to that virus
  • Prototypical: This involves a case which is ahead of the curve in some way and has the capacity to set a trend. A particular African town or city may be a free bicyle loan scheme and the experiences of that town might suggest a future path to be followed by other towns and regions.
  • Most similar cases: Here you are looking at more than one case and you have selected two cases which have a preponderance of features in common. You might for example be looking at two schools, each of which teaches boys aged from 11-15 and each of which charges similar fees. They are located in the same country but are in different regions where the local authorities devote different levels of resource to secondary school education. You may have a project in each of these areas and you may wish to explain why your project has been more successful in one than the other.
  • Most dissimilar cases: these are cases which are, in most key respects, very different and where you might expect to find different outcomes. You might for example select a class of top-ranking pupils and compare it with a class of bottom-ranking puils. This could help to bring out the factors that contribute to or detract from academic success.

Advantages and Disadvantages of Case Study Method


  • It helps explain how and why a phenomenon has occurred, thereby going beyond numerical data
  • It allows the integration of qualitative and quantitative data collection and analysis methods
  • It provides rich (or ‘thick) detail and is well suited to capturing complexities of real-life situations and the challenges facing real people
  • Case studies (sometimes illustrated with quotations from beneficiairies/ stakeholder and with photographs) are often included as boxes in project reports and evaluations, thereby adding adding a human dimension to an otherwise dry description and data.
  • Case studies may offer you an opportunity to gather evidence that challenges prevailing assumptions about a research problem and provide a new set of recommendations applied to practice that have not been tested previously.


  • Case studies may be marked by a lack of rigour (e.g. a study may not be sufficiently in-depth or a single case study may not be sufficient)
  • Single case studies may offer very little basis for generalisations of findings and conclusions.
  • Case studies often tend to be success stories (so they may involve a degree of bias).

Where to next?

Click here to return to the top of the page, here to return to step 3 (Data checking) and here to see a short worked example of a metrics-based evaluation.