Simply put, a case interview is the analysis of a business
question. Unlike most other interview questions, it is an
interactive process. There are three types of case
interviews: business cases, guesstimates and brainteasers.
Case interviews are not focused on your educational, professional
or experiential qualifications, but are designed to assess how you
think and solve problems. Your interviewer will present you
with a business problem and ask for your opinion. The
majority of case interviewers don't have a specific answer that
you, the candidate, are expected to give; and specific knowledge of
the industry in question may be a bonus, but is not
necessary. What the interviewer is looking for is a thought
process that is at once analytical and creative-what consultants
like to term "out-of-the-box" thinking. Following your case
interview, your interviewer may complete a written evaluation
form. This form often includes a list of qualities, traits
and abilities, and asks the interviewer to assess the candidate in
the following areas: leadership skills, analytical skills,
presentation skills, energy and enthusiasm, attention to
detail/organization, quantitative skills, flexibility, maturity and
intelligence.
Business Cases
The classic and most common type of case interview is the
business case, in which you are presented with a business scenario
and your job is to ask the interviewer logical questions that will
enable you to make a detailed recommendation. Most cases are
presented in oral form, though some involve handouts, and a few are
entirely written. A more recent variation is the group case
interview, where three to six candidates are grouped together and
told to solve a case cooperatively while consultants from the firm
watch as silent observers.
Guesstimates
The approach to guesstimates is basically the same as business
cases-you will showcase your ability to analyze a situation and
form conclusions by thinking out loud. The difference here is
that you will not necessarily be using a series of questions to
gather feedback from the interviewer. Instead, you will drive
toward a conclusion through a series of increasingly specific
statements. The interviewer will be evaluating your poise and
professionalism, but don't lose your cool. Remember, there is
no right answer, and feel free to take notes so that you are able
to keep track of your calculations. One former consultant
advises, "Don't be anal. You should realize that for the
purposes of a guesstimate, 1,000,553 is the same as a million, and
you can divide by 350 if you need to divide by the number of days
in a year."
Brainteasers
Brainteasers are very unstructured, and some have no set answer;
therefore, it is difficult to suggest a step-by-step
methodology. Instead, the interviewer is assessing your
reasoning skills, creativity, composure, ability to deconstruct the
problem, poise under stress and your ability to ask directed and
relevant questions. Be sure to take notes as your interviewer
gives you your brainteaser, especially if it's mathematical in
nature.
For Case Interview Questions, please see a Career
Advisor.
Resource: Vault's Guide to The Case Interview