Candidate led and interviewer led cases are often considered to be worlds apart. However, in our view the gap between the two styles can be easily bridged. And often the reasons for exacerbating differences between the two styles have more to do with the cash flow needs of companies selling prep material than with the real differences. A deep understanding of the two styles of cases will enable us to gauge differences and similarities.
Candidate led cases
Candidate led cases are all about your ability to crack a broad problem. Expect questions like:
"Your client is considering entering the Chinese market. What should the client do?"
“How much would you pay for a Coffee Shop in central London?"
In a case like this, you are expected to lead the case. The interviewer will be your greatest asset, since he’s got data and information. In order to successfully crack the case, make sure to follow some key steps:
- Understand the problem: based on the initial question ensure a proper understanding of the problem and the context the business is facing. The level of detail should be what is necessary to grasp what the interviewer is talking about and ensure to hit the right target. However this is not the solution to the case, but just an introduction.
- Lay down a structure: based on the information you get through your clarifying questions, set up a structure that is relevant to the case. For example if you are dealing with a profitability issue, set up a profitability structure. Your structure will help you to pinpoint the areas you are going to cover. Test your structure with the interviewer to ensure his buy-in. Again this part is not the solution, but it’s like creating a path or a set of areas that you’ll investigate with the interviewer.
- Conduct a thorough investigation: dig deep into your hypothesis to discover possible solutions, don’t just scratch the surface. Make sure to ask questions that are specific and relevant. Interviewers’ approaches will vary: some will not want to guide you towards the solution, while others will appear to be solving the case with you.
- Keep track of all data: interviewers will be interested in the synthesis, i.e. how you draw your conclusions. Also, new information might urge you to take some steps back. A good structure and thorough notes are key!
- Be ready to include other aspects/reshuffle your structure and hypotheses as soon as it becomes clear what the decisive factor is.
You can expect on average 50% of your interviews to be in the interviewer led style. This is extremely common in Bain and BCG, while a bit less common in McKinsey. Lots of forums and blogs assert that McKinsey has abandoned the candidate led type and is only using the interviewer led. This might be true for the first rounds, but in general the proportion of candidate led cases decreases with the seniority of the interviewer. Partners, including the ones in McKinsey, tend to give more interviewer led cases, both because they care a lot about candidates’ leadership and because they are too busy to carry around scripts and graphs for the interviewer led cases.
Interviewer led cases
Interviewer led cases are pre-structured cases. The sequence is usually as follows:
- You will be presented with a problem (data may or may not be provided) and after clarifying questions you will structure the problem by being as specific as possible. The initial part is essentially the same as in candidate-led cases
- The interviewer will ask you a set of pre-determined questions, regardless of what your initial structure is. You will have to understand the problem, come up with a mini structure, ask for additional data (if necessary) and come to the conclusion that answers the question.
Essentially interviewer led cases are big cases with lots of mini-cases within them. The method you have to follow is basically the same as in the candidate led cases, the main difference being that instead of solving one big case you are solving several mini cases. Good examples of interviewer led cases can be found in the sample cases on the McKinsey website.
An interviewer led case does not look like a massive challenge. However, despite the skills tested being very predictable, candidates tend to fall into 3 traps:
- Being passive: you should always be the leader of the conversation. Usually the best way is to keep the big picture in mind. It is very important to relate each question or “mini-case” to the big issue the case wants to solve. And the ability to look at the big picture is what makes CEOs different from analysts.
- Forgetting about MECEness: In the “what else?” type of question make sure to come up with a list of ideas that is at the same time exhaustive and without overlaps. In other words, when asked how to grow sales in a supermarket, you should not answer “by increasing customer retention and growing the total number of customers” because increasing retention leads to increasing the total number of customers (not MECE). A MECE answer would have been instead: “by increasing customer retention and growing the number of new customers”, since there are no overlaps between the two levers: through the former you act on existing customers, through the latter on new customers.
- Getting cornered: questions are sometimes used to assess your capability of handling pressure. The interviewer might play the bad cop, deliberately cutting your time or showing disappointment and lack of patience. Keep calm and carry on. Chances are that you are actually doing very well in the case.
Conclusion
Whilst it is good to gain awareness about the differences between candidate led and interviewer led cases, the skill set being tested is very similar.
At My Consulting Coach, we developed our case interview coaching programmes to ensure you are in the best position to crack both interviewer led and candidate led case interviews. First, we ensure that you acquire a sound technique to solve all types of cases. Second, we train you to handle pressure and uncertainty, so that no question or interviewer will take you by surprise.
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