What not to do in a case interview - Part I

Me: Our client is a petting zoo that has lost revenue because of repeated animal attacks on children. Our client hired your team to help them turn around this problem. What should they do? 

Interviewee: Can I have 60 seconds to collect my thoughts? 

Me: Sure, go ahead. 

*Try to look like I'm emailing important, C-level clients as I furiously play candy crush*

Interviewee: I look at this problem as having FOUR parts, the Company, the Customer, the Competition, and the Market as a whole. Let me talk you through my issue tree. 

DING. Failure. Completely wrong answer. For the rest of the case I will be thinking about whether I should join a new tribe on World of Warcraft or stick with my current group of clowns, even if we can't seem to do anything beyond attack each other. 

*********

At this point, 90 seconds into the interview (assuming we started with the case) I know that this candidate is NOT getting an offer. The rest of the interview is mostly meaningless. 

It's possible this candidate can recover with an incredible personal experience study and a perfect job on the rest of the case but I have never seen a candidate recover from something like this. 

And the kicker is probably 50% of candidates start their interview this way. 

Tomorrow I'll explain WHY this is a disastrous case performance. 

Also note that the majority of prep materials, from Ace the Case to CaseInterview.com often suggest that you should start a case like this.

That should tell you the value of that advice. 

One more point - before taking advice from a case prep service in order to prepare for a mckinsey interview, always ask:

(1) Did the person giving this advice work for McKinsey?

(2) If yes, was the person interview trained? (Only happens ~1 year into being an associate)

(3) If yes, did the person do interviews?

If the answer to any of those questions is no, take the advice with a big grain of salt.