When to ask questions and when to proactively make assumptions

Hi Clemens,

Honestly, it depends on the case and the company you are interviewing with (at McKinsey you almost never have to make any such assumptions, an interviewer gives you all the data you need). 

But the best way is just to ask "shall I make some assumptions or do we have more data?". That's it. This is not going to hurt you in any way and you will make sure you are going into the right direction.

Hope this helps!

Best,
Daniel

Hello Clément!

Thanks for the detailed writting in your post :)

The right answer here, altough it can be a little disappointing to you, is "depends". None can give you an axiom of "3 questions are good, 2 are better, 4 are too many", since it totally depends on the case and the way in which it is being conducted. 

Hence, never forget that a MBB consulting interview is, above everything, a conversation, and you need to have your 5 senses ready to adapt to it. This totally applies to the number of questions!

It´s good tough that you give a precise example, like this is easier to give you accionable feedback. For that case in particular, again, also depends ;)

• If you know "more or less" what the populations can be, you can give an educated guess and ask for correction: "I know that Germany´s population is arround 80 MM people, is this correct?"
• If you don´t know, don´t jump into the pool without knowing whether there is or no water! You don´t want to look as a fool either! None is supposed to know all the populations of over 300 countries, so just ask. 

Practicing and getting good feedback on your agility and communication is the only way to get more and more "calibrated" and know when it´s ok to keep asking and when you should start making educated assumptions. 

Hope it helps!

Cheers, 

Clara

Hi Clément,

I think the best approach for you in this situation is to put yourself in the shoes of a consultant working on a client engagement and think of you interviewer as the client.

Would a client like to see you spending time looking for a number that he already knows? Probably not!

If you need an information the best thing you can do is to ask for it. You should not loose time making assumption if the data you need is already somewhere. Moreover, making assumptions inevitably reduces the precision of your final result.

You should just be careful of the following thigs:

- Drive the interviewer through your reasoning, making sure to state clearly why you need certain data

- Make sure to decompose the problem to its very basic components and start asking for info on that

You can be sure that if the interviewer wants you to estimate a number you will have to do it for sure over the case, no need to overcomplicate your life trying to estimate more than needed.

Hope this helps,

Don't hesitate to get in touch with me if you need any more tips,

Best,

Ale

Hi Clement, 

This is a very good question. Indeed some of my coachees ran into similar problem. Here are my perspectives. 

1) Asking question is good, but make sure you ask relevant questions. Before you bring it out to your interviewer, quickly ask yourself would the answer to the question be helpful to address the client problem or not. This takes some practice to be really fast and efficient, when it become natural to you.

2) When asking question regarding assumption, don't just throw the question to your interviewer. That would make him/her feel you are asking him/her to solve the case for you. State your assumption (and the reason backing it up) and then validate with your interviewer. E.g. If I need to estimate the total seats in a football stadium (I know almost nothing about football btw), I would tell the interviewer "Even though I am not familiar with football stadium, I have been to a sport stadium in Singapore for concert; and based on my knowledge of the concert they sold X amount of seats and the stadium was roughly Y% full, so I estimate the total seats to be X/Y%=Z. Do you think my estimate is in the right ball park?" 

Hope it helps,

Emily

Hi Clément,

please find below the answers to your questions:

Should I ask first for the data, or should I proactively make assumptions, knowing that if I'm too far away the interviewer will correct me?

For business cases, the short answer is that you should never make assumptions. Instead, you should state which are your hypotheses and verify them with data. That’s simply because it's what you would do in a real project.

Bad example

“I assume Germany has a bigger market size, so would start my analysis there”

Good example

“My hypothesis is that Germany should have a bigger market size due to the higher average income. Do we have any information on whether income is a driver for purchase in this case and whether that’s the only relevant element?

Market sizing questions are different, as you normally have to make an assumption - although also show a rationale for the assumption itself.

If I ask a question but the interviewer responds something such as "make an assumption" or "what do you think?", does it mean I should have make an assumption in the first place and not asking the question?

Not necessarily. It could just mean the interviewer wants to test your business acumen. Anyway as mentioned before you should state hypothesis rather than make an assumption on a particular situation.

Hope this helps,

Francesco

Hi Clement, the more you do the more balance you are going to find between these 2 approaches. It depends on cases and on interviewer style (you should read the feedback during the case), but generally speaking, my recommendation is to ask "proactive questions" by do not request for broad-generic help but try to proactively insert your response while you are asking a question (e.g. I suppose the main cost item for our client are A B C, do we have a breakdown?)

Hope this helps,
Antonello