Case study interviews are probably the most difficult to master, purely because they are never generic. They are designed to test your problem solving approach and method. Therefore many people tend to struggle with coming to grips with how to prepare for case interviews.
If you are one of these people, then here are some tips to help get you more prepared for your next case interview:
Practice your mental arithmetic
This is a vital step for how to prepare for case interviews; I am not saying become they next Albert Einstein – but rather to focus on how to do basic mental calculations like percentages. This will help when trying to work your way through a case interview question such as: “Tell me how many windows you think are in this country?” I am sure that they don’t have the answer themselves however the way you simplify and talk your way through the problem is critical; in this case the idle time doing simple math with a calculator will put you on the chopping block with the recruiter.
Learn the process
As mentioned previously it is very difficult to learn similar examples of case study questions. Taking this into consideration, the best way for how to prepare for case interviews would be to learn the process rather than the exact details used in case study examples. Try to create a mental model of how you would approach case studies. Take the following into consideration when doing this:
- Learn how to make logical assumptions
- Learn to fully utilize all information
- Never lose sight of the main question – it is easy to do this when different ideas are floating through your head
- Learn to ask the right questions to get a clear perspective of the problem
Don’t overthink it
When you overthink a problem to try and impress the recruiter – you end up actually having the opposite effect. The trick behind case study interviews is to make simplifying assumptions; it is not meant to be difficult mathematics. Therefore, you should always aim to make justified assumptions about the problem. For example, a question such as: “How many people in this country take the bus?” would start off with a simplifying assumption that not everyone takes public transport thus reducing the number of people used in the calculation.
Understand that you can never be fully prepared
Never beat yourself up when you perform poorly at case study questions because they are dependent on two things which are not easy to develop instantaneousy:
- Your level of problem solving skills
- The technical knowledge surrounding the problem
Practice your listening skills
Listening is one of the most important aspects of answering case study interviews well. Be prepared for a lot of facts which you will need to keep in mind while working through the problem. Constantly asking the interviewer to re-iterate what they said doesn’t look good on your comprehension abilities. On the same note – never be afraid to ask questions to clarify a problem – the nature of case study questions are such that they are open ended and clarification of details are required to make correct assumptions and give meaningful solutions.