Best practices for structuring notes during a case interview

Hi,

I'm having trouble to taking structured / clean notes during a case interview. Especially when it comes to math notes. Basically I have 2 sheets. One for the case and one for the maths. Both are in landscape mode.

  1. The one for the case is (at the top) the prompt of the case + the objectives and (below the prompt) my structure. Sometimes a tree (profitability, market sizing), sometimes boxes for areas of investigation (business situation, market entry, operational cases, etc..)

  2. The one for the maths is when I need calculations and it ends up being lots of numbers jotted down without any structure. And it becomes just chaos to read for someone else.

So two things: - For the case sheet: If the initial structure is good, then don't need to worry. But if I need to rethink my structure during the case, should I take another sheet or deprecate my old structure and write it again on the same sheet? And how to be clean (interviewer friendly) when doing this?

  • For the math sheet: How can I organize my sheets so I can have clean plain words formula (# customers = pop x penetration rate x market share...) along with the numbers well presented to the interviewer AND my dirty math (like multiplication or division decomposition, simplification of my fractions, etc...) which I find is hard to be structured in the first place.

Anyway, more broadly, how do YOU organize your notes in details? Especially the maths?

Thanks :)

3 Comments
 

Thank you Roy-Ray for your reply.

Actually I'm not talking about math skills but structuring my notes on the sheet. I do use scientific notation as it is indeed helpful to not miss 0's.

In favt, I'm more talking about your 1st point. Math should be neat. But as I have the feeling that math should be done quickly because it's hard to compute and talk at the same time (so it's a silent moment during the case interview). And when I want to do quick math computations with more than 1 step (say with 3-4 intermediate results), I end up having division or multiplication decomposition / simplification, intermediate results (which are not part of any equation) and my equations written down on the same sheet.

Result: my initial equations (e.g. # customers = population x % penetration rate x frequency x % market share ...) that should be presented to the interviewer become polluted by raw numbers that come from my "dirty math".

What's your beat practice on that? Do you use an additional sheet for raw math, do you split your math sheet in 2 (one side for neat formulas and result, one for dirty math)?

 
Best Response

1. Give short titles to your calculations

As you clearly stated, you have a sheet for your structure and a sheet for your math, so use them.

While outlining your structure on the first sheet, try to give specific numerical names to all the branches of your issue tree (or to all the boxes). So, if you're solving a profitability case, then write "1" near the revenue branch and "2" near the costs branch (variable costs will be "2.1", while fixed costs will be "2.2").

Now when you do your math on the second sheet, give the corresponding numerical names to all your calculations. Thus, for example, write a short title "2.1" near your calculations of variable costs.

This will bring a bit of structure to your messy second sheet.

2. Be neat and ask for 10 seconds for calculations

There's nothing wrong in taking 10 second silent brakes for your calculations during the case interview. Don't be afraid of the silence — it's better to stop for a second, make neat calculations and present your result to the interviewer than to make a stupid mistake. And again, when you keep silent it's easier to concentrate and to start writing neatly (which is actually a problem for you, as I understand).

3. Don't use the whole first sheet for the first issue tree

Typically, you change your hypothesis and the corresponding issue tree a few times during the case interview. Thus, keep some space for the next issue trees on your first sheet. You can put at least 2 issue trees on one sheet. However, if you are out of space, it's OK to ask for a new sheet. Don't hesitate to do it.

Good luck!

 

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