Whether interviewee-led or interviewer-led, you still need to display essentially the same qualities, including how you structure.

Also, remember the main objective is not to crack the case, but to convince your interviewer you can build a structure, follow it, ask the right questions, draw the right insights, and work towards a recommendation. Actually cracking the case is a mere result of the process. If you follow the process, I know you will crack it, given enough time.

Last but not least, and as Mathias suggests, cases may have more than one answer... Life isn't black & white, cases aren't necessarily either.

Hi,

First of all - McKinsey has both interviewer and candidate led cases. So make sure you can do both. Answering your questions:

1. It doesn't matter which type of case it is - it mostly depends on the interviewer. Some of them will give you a clear context and unclear objective. Other - objective with no context. So you should always be asking clarifying questions just to be on the safe side if the interviewer did not state a measurable objective / not provided properly the context and business model!
2. There is no standard answer. As long as your answer makes sense, is well-structured and you are asking the right questions - its good.

Best

Thank you very much the excellent questions:

1) Even if a case is interviewer-led, you are still required to ask clarifying questions. The difference is merely that the interviewer will guide you in a general direction (e.g. you have come up with the initial structure A/B/C/D - the interviewer might then ask you to start with C and give you some additional information on the topic. Moreover, the interviewer is generally responsible for driving the case to its conclusion and will ensure that you are able to cover the most important points during the 30-minutes.

2) From my experience, cases are generally not graded in a binary way (right/wrong, yes/no) but rather on a range. Moreover, it is often not about getting the exact answer right, but rather about demonstrating your ability to structure and present a logical answer. In fact, I have seen many McKinsey cases that are extremely ambivilent and don't necessarily have an obvious answer.