Guide to case studies

What is a case study?

A case study is an in depth focussed study of a person, group, or situation that has been studied over time within its real-life context.

There are different types of case study:

  • Illustrative case studies describe an unfamiliar situation in order to help people understand it.
  • Critical instance case studies focus on a unique case, without a generalised purpose.
  • Exploratory case studies are preliminary projects to help guide a future, larger-scale project. They aim to identify research questions and possible research approaches.

We are often looking to develop patient stories as case studies and these will use qualitative methods such as interviews to find specific details and descriptions of how your subject is affected.

Patient stories are illustrative or critical instance case studies. For example, an illustrative case study might focus on a patient with an eating disorder to provide a subjective view to better help trainee nutritionists understand the illness.  A critical instance case study might focus on a patient with a very rare or uniquely complex condition or how a single patient is affected by an injury.

How do you do a case study?

1. Get prepared!

  • Be very clear about the purpose of the case study, why you are doing it and what it will be used for?
  • Think about the questions you want to answer? What are your research or evaluation questions?
  • Determine what kind of case study will best suit your needs? Illustrative, Critical Instance or Exploratory?
  • Define the subject of study – is it an individual, a small group of people, or a specific situation?
  • Determine if you need ethical approval to conduct this case study – you may be asked to prove that the case study will do no harm to its participant(s).

2. Get designing!

  • Finalise your research or evaluation questions – i.e. what you want to know at the end of the study. Limit these to a manageable number – no more than 4 or 5.
  • Think about where you will find the information you need to answer your questions.  Interviewing research subjects and/ or observing will likely be the central methods of your case study, but do you need to look to additional data sources as well? For example, desk research or evidence/literature reviewing, interviewing experts, other fieldwork and so on.
  • Create a plan outlining how you will gather the information you need to answer your research or evaluation questions. Include a timeframe and be clear that you have the resources and equipment to carry out the work. Depending on the nature of the case study or the topic being studied a case study may require several meetings/interviews over a period of many months, or it might need just a one off interview. What does yours need?
  • Decide on the exact subject of the study. Is this a specific person or a small group of people? If yes, plan how you will get in touch with them and invite them to take part in the case study. How flexible can you be in terms of time and travel? Does this limit your access to potential participants?
  • Design interview questions that are open and will enable the participant to provide in-depth answers. Avoid questions that can be answered with a single yes or no and make sure the questions are flexible and allow the participant to talk openly and freely.

3. Get recruiting!

  • You may have a specific individual in mind, or specific criteria. You will need to invite people to participate and make very clear that they are able to withdraw at any point.
  • You will need consent from the participants. Make sure the purpose of the case study, why you are doing it and what it will be used, the methods and time frames are extremely clear to the potential participants. You will need written consent that demonstrates that the participant understands this. Additionally, if you intend to digitally record an interview or take notes, make sure you have permission from the participants’ first.
  • If your central method is observation, this will be open observation – the participant must be aware of your presence and agreed to it – you are not allowed to observe without the participants’ permission!

4. Get conducting!

  • Interviewing – Agree a mutually suitable time and venue for the case study interview. This may be a one off or the first of many over several months. Make sure the participant is in an environment they are comfortable and able to talk in. Equally important, however is that the environment is safe for you and is conducive to conducting a case study interview – i.e.  If it is a private space, are you safe? If it is a public space make sure it is not too noisy or likely to be affected by interruptions.
  • Decide what is the best method of recording the interview information – digital recording is less intrusive and you can engage better in the conversation, than if you attempt to just take notes. Taking notes can mean that your concentration is focused on the writing rather than the listening and you can miss vital points. It can also be off-putting for the participant if there is no eye contact because you are scribing throughout the conversation. However, some participants will not like to be digitally recorded – so it is best to discuss this with them first. If you are digitally recording always test the equipment first. Even if you are digitally recording you will still need to take notes on key points, or things that you would like to investigate further, questions that arise or points at which you don’t want to interrupt the conversation or anything that will not be captured by the recording, such as body language or other observations.
  • Depending on the total length of your case study, you might hold a one off interview, interview weekly, once every month or two, or just once or twice a year. Begin with the interview questions you prepared in the preparation and design phases, then iterate to dig deeper into the topics. Ask about experience and meaning — ask the participant what it’s like to go through the experience you’re studying and what the experience means to them. Later interviews are an opportunity to ask questions that fill gaps in your knowledge, or that are particularly relevant to the development of the case study or in answering your questions.
  • Observing – recording observation can be done manually – i.e. taking notes – or digitally via a camcorder or similar. It is important to capture detail about the subject/participant and their interactions with others and the environment, their behaviour and other context an detail that is relevant to your questions.

5. Get analysing!

  • Write up your notes or transcribe (Interviews), make notes (video) from your digital recording. Remember that if you are transcribing it is important to include pauses, laughter and other descriptive sounds and commentary on tone and intonation to better convey the story. Include the contextual information / the external environment and other observations that are important. Such as when and where the interview took place (you will not necessarily make this public) and any issues that arose such as interruptions that affected the interview or if there were multiple interviews anything of significance that happened in the periods between interviews.
  • Thematically code (look for themes) and look for key parts of the interviews that will answer your original questions. Also be very aware that the may be new or unexpected information that has come through the process that is very important or interesting.
  • Arrange the notes or transcriptions from the interviews and, or observations into a case study. It is not likely that you will be able to use the transcriptions without reorganising them, but if you are rewriting the story in your own words, be careful not to lose the meaning and language that reflects the participant.

6. Get sign off!

  • Once you have drafted your case study make sure the participant(s) have sight of it and an opportunity to say whether you have captured their story and are representing it/them as they would like.

7. Get disseminating!

Top tips

  • Remember case studies are not designed for large group studies or statistical analysis and do not aim to answer a research question definitively.
  • Do background/context research where possible.
  • Establishing trust with participants is crucial and can result in less inhibited behaviour. Observing people in their home, workplaces, or other “natural” environments may be more effective than bringing them to a laboratory or office.
  • Be aware that if you are observing it is likely that because subjects know they are being studied, their behaviour will change.
  • Take notes -Extensive notes during observation will be vital.
  • Take notes even if you are digitally recoding an interview to capture your own thinking, points to follow up on or observations.
  • In some case studies, it may be appropriate to ask the participant to record experiences in a diary – especially if there are periods between your interviews or observations that you wish to capture data on.
  • Stay rigorous. A case study may feel less data-driven than a medical trial or a scientific experiment, but attention to rigor and valid methodology remains vital.
  • When reviewing your notes, discard possible conclusions that do not have detailed observation or evidence backing them up.
  • A case study might reveal new and unexpected results, and lead to research taking new directions.
  • A case study cannot be generalised to fit a whole population.
  • Since you aren’t conducting a statistical analysis, you do not need to recruit a diverse cross-section of society. You should be aware of any biases in your small sample, and make them clear in your report, but they do not invalidate your research.
  • Useful resource: ‘Case Study Research: Design and Methods’, Robert K Yin, SAGE publications 2013.