How to Read Charts in a Case Interview

Earlier today I read a PrepLounge (consulting prep) site blog post regarding chart reading in case interviews.  An individual had posted a question to the site inquiring about the best way to prepare for this type of question.  Several current or former consultants responded and shared tips based on their own personal experience. See the highlights of those responses below.  I thought each responder made some valid points .  You may find advice that could prove useful in your preparation.    To see more, I recommend going to www.PrepLounge.com.  You may want to sign up for the email feed to get advice, updates and post feeds from the site.  I have found them to be useful!

RESPONSE #1

“In general, your interviewer may ask you to read a chart and interpret it in a consulting interview. These may be all types of charts, hence you should be familiar with the basics of chart reading. The key here is always to

  1. describe what you see: think aloud while trying to understand the chart. Thereby your interviewer will be able to follow your thought process
  2. contextualize the chart: put the chart into the overall case context – what was the main question? How does the chart fit it? Does it change any of your assumptions?
  3. interpret: interpret what you see and how it fits with the context. What implications may this have to the overall case? It makes sense to state some initial hypotheses. If there are numbers on the chart, use these numbers to quantify your hypotheses and to show your interviewer that you already think one step ahead.

There is a good tutorial on Preplounge that explains the steps I just explained in more detail.”

RESPONSE #2

“I would follow 5 steps to read a chart:

  1. Take one minute of time to read the graph. It is always good to ask for a minute to digest the graph.
  2. Summarize what the graph is about. After you have analyzed, present the interviewer the main elements of the graph.
  3. Restate the main question you have to answer. Missing this step is one of the most common mistakes done by candidates. Before moving to the analysis, you should have clear what you have to answer. The easiest way to clarify it is to repeat what you have to achieve with the graph analysis.
  4. Provide an analysis related to the question.After restating the objective, present to the interviewer the main insights that you can derive from the graph.
  5. Provide a conclusion for the graph that answers the original question and present the next steps to follow based on such conclusion. A good candidate would present the conclusion of the graph. A great candidate would do this and also present the next steps to follow to answer to the main client’s request.”

RESPONSE #3

“You can use the following approach:

  1. Take a minute to look at the graph
  2. Read the graph title
  3. Look at the graph type and define the type (pie chart, line chart, etc)
  4. Look at the legend (ask for clarifying questions if necessary)
  5. Identify whats going on on the graph. Look for: Trends, % structures,
  6. Look for unusual things – correlations, outliers,
  7. Make 3-4 conclusions from the graph. Think of potential hypothesis on what could be the root cause / what are the consequences
  8. Prioritize the most important for your current analysis and move forward with the case

Sources to learn from (prioritized):

  1. Study “Say it with Charts” book by Barbara Minto
  2. Learn basic statistics (Any GMAT or MBA prep guides)
  3. Check all available MBB presentations and publications. Practice to derive conclusions and check yourself with the actual ones from the article/presentation
  4. GMAT IR part (Official guide and Manhattan prep)
  5. “Consulting Bible” and “Vault guide for consulting” – check the chapters on cases with graphs in these books”

RESPONSE #4

“Use what I call the McKinsey way:

– first read “around the chart” then “into” it. Lots of context for the data is written around the graph.

– focus on “insights”. Whenever I show a graph to someone where the profits were growing from yr1-5 and falling from yr5-7 but margins were falling much faster from yr5-7, and if they come back repeat that same info to me, they get rejected in my book. I can SEE the graph, tell me something DEEPER. For example, tell me that margins falling faster than revenue is likely because it’s a fixed cost heavy biz.

– get good at narrowing down what you want to focus on in the graph. If your case is about P&L, focus on finding about profits, costs, F & Var costs, etc. Do not over-rotate on margins/profitability. Do NOT waste time trying to mentally calculate margins fell by 22.67% in year 2-4 — it may impress the interviewer but not at the cost of you actually telling her something that takes the case forward!”

By Kim Austin
Kim Austin Director