The first minute after the case prompt tells an interviewer a lot. Before you have drawn a single framework, your clarifying questions show whether you understand what kind of problem this is.
I interviewed candidates at McKinsey for most of my five years there. Two kinds of clarifying questions made me lose interest almost immediately. Here they are, what to ask instead, and good questions for each common type of case.
The first kind: asking for data
“What’s the market size?” “How fast is revenue growing?” “What are the client’s margins?”
These are fair things to want to know. They just aren’t clarifying questions.
In most cases the interviewer will give you that data later, usually with an exhibit, at the point in the case where it matters. Or they expect you to estimate it yourself. Asking for it up front sounds like you want someone else to do the work, and it usually gets the answer “we’ll come to that.”
The test: would the answer change how you structure the problem, or is it a number you will need later? If it’s a number you will need later, wait.
The second kind: the canned question
“What’s the goal, and what’s the timeline?”
I heard this in almost every interview, and it always sounded rehearsed. It comes from prep books, and interviewers know it.
Most of the time (not always) the goal is already clear from the prompt. If the CEO wants to know whether to acquire a company, the goal is to decide whether to acquire it. And the timeline is almost always as soon as possible.
If you genuinely aren’t sure what the client is optimizing for, don’t ask. State an assumption and keep going:
“I’m assuming they want to improve margins as quickly as possible. Let me know if that’s not right.”
That shows judgment. You’ve read the situation, made a reasonable call, and given the interviewer an easy way to correct you.
What a good clarifying question sounds like
A good clarifying question asks how the business works, because that changes how you solve the problem:
- How does the client actually make money?
- Who is the customer, and who pays? (They are not always the same.)
- What exactly is sold, and through which channels?
Here is why it matters. Take a case where a home cleaning company’s profits have fallen. One question changes everything:
“Do they employ the cleaners themselves, or do they franchise the brand and collect a fee from local owners?”
If they employ the cleaners, profit lives in wages, travel time between homes, and how full each cleaner’s day is. If they franchise, they earn a royalty on each franchisee’s sales, so the questions become how many franchisees they have and how much each one sells.
Same prompt, two completely different businesses.
That is what an interviewer is listening for. Not a checklist of questions, but whether you understood the business before trying to solve its problem.
Good clarifying questions by type of case
One or two per case is usually enough. Pick the ones whose answers would change your structure.
Profitability “Profits are falling. Why?”
- Is the decline across the whole business, or in one product, region or channel?
- How does the business make money: one product or several, one-off sales or recurring?
Market entry “Should the client enter this market?”
- Does the client have any experience in this market, and why are they considering it? Is there a reason beyond the financial return?
- Is there a particular bar the entry has to clear for the client to call it a success, such as a revenue target, a market share or a payback period?
M&A “Should the client acquire this company?”
- What does the target sell, and how does that relate to what the client already does?
- Is the client a company in the same industry or a financial investor? It changes what value looks like.
Pricing “How should the client price this product?”
- Who is the buyer, and who is the user? You are making sure you know who actually pays, because that is who the price has to work for. (In healthcare and business software the payer and the user are often different people.)
- Is this a new product or a price change on an existing one?
Growth “How can the client grow revenue?”
- How do they make money today?
- Is there any constraint on how they can grow, such as capacity or regulation?
Operations or costs “Costs are too high.”
- What does the process look like from order to delivery?
- Which cost is the client worried about: total cost, or cost per unit?
How to ask them well
- Say why you are asking. “I’m asking because it changes where the profit problem could be.” One sentence turns a question into evidence of judgment.
- Keep it short. Two or three questions, then start. A long round of questions before your framework reads as stalling.
- Use the answer. If you ask whether they employ the cleaners, the answer should show up in your framework. Asking and then ignoring the answer is worse than not asking.
- If the interviewer says “we’ll come to that,” take it as a signal, not a rejection. Move on.
Frequently asked questions
How many clarifying questions should I ask in a case interview?
Usually one to three. Ask only the ones whose answers would change how you structure the problem, then start.
Should I ask about the client’s objective?
Only if it is genuinely unclear from the prompt. Most of the time it is clear. If you are unsure, state an assumption (“I’m assuming they want to improve margins as quickly as possible”) rather than asking a rehearsed “what’s the goal and timeline?”
Can I ask for data in my clarifying questions?
Avoid it. Data usually comes later in the case, when it matters, or you are expected to estimate it. Ask about how the business works instead.
What if I can’t think of a clarifying question?
It’s fine to have none. Say you have a clear picture and move to your structure. No question is better than a filler question.
In The Case Room you run a full, spoken case, and the interviewer answers your clarifying questions the way a real one would, then shows you what to sharpen for your next case.
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