How to Interpret Charts and Data in Case Interviews

Last Updated on March 27, 2024

On your journey to solve the case in a case interview, you must sort through and interpret data presented in the form of charts and data tables. The exhibit interpretation in a case is usually the most straightforward section since it is the only part of the case where you do not need to come up with new content, rather read and interpret what is already there.

Still, it is an essential skill you need to learn and master to rank highly with your interviewers. Mastering case interview charts is crucial for candidates aiming to excel in consulting data analysis.

In fact, 90% of consulting case interviews will have you interpret charts and data or 100% of top-tier firm interviews such as McKinsey, BCG, and Bain.

This article is part of our consulting case interview series. It aims to teach you how to interpret charts in consulting interviews, ensuring you’re well-prepared to tackle this aspect of the process. For the other articles, please click below:

• Overview of case interviews: what is a consulting case interview?
• How to create a case interview framework
• How to ace case interview exhibit and chart interpretation (this article)
• How to ace case interview math questions

Charts and Exhibits in Consulting Case Interviews

Before diving deep into specific charts, let’s understand the basics of mastering data analysis for consulting case interviews.

Two types of exhibits

Exhibits in presentations and analytical reports in case interviews generally fall into two primary categories, each with its unique approach to data visualization:

1. Charts – This category encompasses a variety of graphical representations used to visualize data, making complex information easier to understand at a glance. These can include but are not limited to, scatter plots that display data points across two dimensions, bubble charts that add a third dimension with the size of the bubble, line graphs that show trends over time, bar charts that compare quantities among different groups, and pie charts that illustrate the proportional breakdown of a whole into its constituent parts. Other visualization tools like histograms, area charts, and radar charts also fall into this category, each offering distinct advantages for presenting specific types of data.
2. Tables – As a more traditional form of data presentation, tables organize data in rows and columns, providing a straightforward way to display numerical values, text information, or both. They are particularly useful for presenting detailed data where precise values are important. Tables enable viewers to compare individual data points directly and are often used to supplement charts by providing the exact figures that the charts represent visually.

Both charts and tables play crucial roles in conveying information, whether it’s financial figures for a company, growth metrics for a market, demographic statistics for a country, or product comparisons among competitors. The choice between a chart and a table often depends on the nature of the data being presented and the message the presenter wishes to convey.

Some charts are better suited for demonstrating trends over time, such as line graphs, while others, like pie charts, are ideal for showing composition. The challenge, especially in scenarios like case interviews, lies in working with the type of exhibit provided, which may not always be the most optimal for the data or context at hand. This requires flexibility and creativity from the interviewee to make the most of the available tools and effectively interpret the underlying data insights.

The challenges to overcome

As a case interview candidate, you need to quickly skim through the data, elicit the key insights, and derive what it means for the situation at hand within the context of the case (the so-what?). Many candidates struggle with this part of the interview since they either do not have a clear approach or are unsure how to spot key insights.

In fact, being able to quickly skim through a wide range of data, elicit the key information, and derive top-down what it means for the question at hand is a key skill that all major consulting firms are looking for in candidates.

You can train this skill and improve your analytical approach to data tables and graphs and along the way improve your overall performance in the case.

Let’s first look at what to expect in a case interview.

Types of Charts and Exhibits in Case Interviews

The good news for you: Firms such as McKinsey, BCG, and Bain always use the same types of charts in their case interviews as well as on the job.

Below is an almost exhaustive library of all charts and common variations you should expect during the case interview, covering 99% of what we have seen in interviews, on the job, and from colleagues.

More often than not, you will be presented with more than one chart and have to interpret and find the key insights by combining the two. Also, sometimes charts can be combined and a bar chart could also contain a line or two from a typical line chart. Understanding a variety of chart interpretation skills is fundamental during your consulting case practice.

As a side note: We have populated the charts with random numbers and random legends to make them appear more realistic as they would look like in a case interview. In practice, each chart can display many things.

Essential chart types for consulting case interviews include bar graphs, pie charts, and scatter plots, among others.

Bar charts

Bar charts are most commonly used when comparing values of several items at a specific point in time, or 1-2 items at several time intervals. Too many items or time intervals have a negative impact on the readability.

One variation you might come across in case interviews is the stacked bar chart. It extends the standard bar chart by one or more categorical variables. Each bar is divided into two or more sub-bars, each one corresponding to a different categorical variable.

Another variation of the bar chart is the 100% bar chart. It’s a stacked bar chart that shows the relative percentage of multiple data series in stacked bars, with the total of each full bar always equalling 100%. Be aware that, while all bars have the same height visually, they do not necessarily have the same total.

The clustered bar chart visualizes multiple sets of data over the same categories (like revenue of two products over three years).

Bar charts are less suitable to illustrate parts to visualize parts of a whole unless they come in a waterfall chart form. A waterfall chart can be either built up to a total or built down from a starting point to a new ending point.

A specific form of a bar chart would be a histogram, which displays an approximate representation of the distribution of numerical data. Histograms can be used to provide insights into mean and standard deviation.  

Line charts

Line charts illustrate time-series data, i.e. development, and trends in data over a specific time period. Contrary to bar charts, they consume almost no space since the points in time are connected by lines, which allows visualizing a large number of time intervals.

They are not used to show data breakdowns and tend to become confusing with more than 5 simultaneous variables (lines).

Pie charts

The pie chart’s core strength is to visualize proportions. They include all parts of a whole, without any overlap in their segmentation. Pie charts can also be displayed as donut chars (same, just with a hole in the middle).

Time series cannot be displayed with pie charts.

Scatter plots

Scatter plots visualize how two variables relate to each other by plotting data points on a matrix. They are an extremely powerful tool to look at the correlation of variables by being able to display an infinite amount of data points, while still keeping readability.

Scatter plots are limited by the number of axes (e.g., two axes can display two variables).

The bubble chart is a variation of the scatter plot that allows displaying the size of a certain data point, thereby introducing a third variable into the picture. The size of the bubble can visualize many things. It usually shows much fewer data points than a scatter plot.

Area charts

An area chart is a combination of a line and bar chart, visualizing how the values of one or more variables change over the progression of a second variable, usually time.

Like a bar chart, there can be different variations such as stacked area charts or 100% area charts.

Spider charts

A spider chart, also called a radar chart, can be used to display multivariate data in the form of a two-dimensional chart with three or more quantitative variables represented on axes starting from the same point. A line connects the data values for each spoke.

Flow charts

Flow charts or process charts visualize a process or a system and its individual parts. They can be used to describe, improve, and communicate simple or complex processes in clear and easy-to-understand diagrams.

Below, I have pasted your consulting application journey, which is well suited to demonstrate the merits of flow charts.

Now that you know what types of charts can show up in a case interview, let’s have a brief look at data tables.

Data tables

Data tables display information in tabular form with labeled rows and/or columns. They are commonly used to display client data (e.g., financial information), market data (e.g., sales information), economic data (e.g., GDP), and population data (e.g., demographics) amongst other things. Their format helps to organize disparate data and permits you to quickly digest it.

The way data is presented in tabular form can differ. For an example of the different stylistic elements a data table can contain, check out the table below. Familiarize yourself with best practices for data tables in case interviews to enhance your proficiency.

We’ve compiled essential tips for consulting case interview chart interpretation to help you excel in your analytical approach. Our guide to exhibit analysis in consulting interviews will walk you through the process, ensuring you’re fully equipped. Employ strategies for effective consulting case analysis to systematically approach each case.

How to Interpret Charts and Data in Case Interviews

To interpret charts most effectively and find their ‘so-what’ to impress the interviewer, you need to demonstrate structured thinking and strong communication whenever you are asked to interpret data in the form of tables, graphs, etc.

A 7-step approach to distinctive chart interpretation

If you want to impress interviewers by interpreting exhibits in the most effective and time-conserving manner, follow these seven steps:

1. Restate and clarify the purpose of your exhibit analysis, i.e., what you want to do with it (candidate-led format) or play back the question you are trying to answer (interviewer-led format). You must be clear about the purpose of the exhibit at the given stage of the case. The exhibit does not exist in a vacuum but is the result of your probing (candidate-led format) or the natural case sequence (interviewer-led format), and it should be looked at with a certain goal in mind, usually to verify a certain hypothesis of yours. An exhibit without context has no purpose. Only if you approach the exhibit interpretation with a clear objective in mind will you be able to spot and interpret the correct insights.
2. Briefly describe what you see on the exhibit by looking at the title, units, labels, legends, columns, rows, etc. You want to familiarize yourself with what you see and play it back to the interviewer in two to three sentences. Keep this part brief.
3. Clarify whenever something is unclear. Never interpret a chart before confirming your assumptions about what is displayed with the interviewer. It could be that you are not familiar with a word, concept, label, or some explanations might be missing. Always be clear about what the chart is covering. For instance, is it our client’s data, is it market data, or is it competitor data? Are you dealing with the general population or a subset of it? Is the chart backward-looking or a forecast?
4. Ask for time to structure your thoughts, usually around 30 seconds to one minute. During that period, write down the key insights, the implications, and the next steps.
5. Communicate your key insights, which are the two to four most important data points on a chart, usually outliers or data points that surprise you. Communicate in a structured, top-down manner.
6. Communicate the implications (the so-what?) proactively, interpreting the data in the context of the case and highlighting what you would recommend based on the available data (what to do) or what the data tells you about the situation at hand (what it means).
7. Communicate the next steps, discussing automatically how you would move forward in a structured manner, for instance, what additional analyses you want to conduct or what concrete implementation measures you would recommend.

This approach is highly effective in guiding your exhibit analysis and decision-making about what to do with the data.

The importance of taking time

I want to stress the importance of taking time to think about your analysis, the fourth step of my approach. This habit is the biggest differentiator between successful and unsuccessful candidates, and I see its impact daily. Unsuccessful candidates try to rush through their analysis, reading and interpreting the chart on the go, all while talking to the interviewer.

As a result, they miss key facts, fail to properly contextualize data for the case at hand, appear unstructured and chaotic, and overall take longer. I remember the disappointed faces of candidates that I challenged based on their rushed analysis and the aha moments that resulted. By thinking about these things beforehand, you can streamline your insight generation, contextualization, and communication. Taking the time comes with two additional benefits:

1. You demonstrate to the interviewer that you can push back under pressure and are confident enough to take time to think (highly relevant when dealing with demanding senior clients).
2. You get additional time to identify what might be unclear related to the information from the interviewer or the exhibit itself. Exhibits might come with missing or unclear labels, units, or legends and you want to clarify what is displayed before discussing the correct insights and implications.

Communicate top-down

Whenever you present an insight during a case interview you should communicate your findings top-down. The same is true when presenting your interpretation of a chart, table, graph, etc. Start with the single most important fact you can extract from the chart.

1. Give the answer or the key insights the interviewer is looking for (“I see three key insights,….”).
2. Discuss the implications of the data, the ‘so-what’ for the client problem you are trying to figure out and find a recommendation for. Tie those findings to the case and your analysis and interpret their implications. (“Based on this it suggests that….”)
3. Move on to the next steps. (“To move this forward I would….”)

Don’t start going in circles; don’t go astray. Stay structured and hit the interviewer with the key points. The interviewer mimics the client and senior clients usually don’t have much time to spare. Every sentence in the chart interpretation part should add value to your analysis. Stay away from empty words and phrases or worse aimless rambling.

By setting your communication up that way, you demonstrate that you are able to

1. Retrieve key insights in a data set quickly.
2. Communicate top-down with senior executives.
3. Consider the impact of the data on the current issue.
4. Move forward.

Also, you give the interviewer a chance to dig deeper to understand your reasoning.

Avoid the Most Common Pitfalls

Candidates often encounter difficulties with exhibit analysis consulting, highlighting the importance of thorough consulting interview preparation.

The 2 key mistakes

Avoid the two most common mistakes I see in almost every initial case with my clients:

1. Do not read back every detail and data point from the chart. A senior partner once told me in the early days of my career that he did not need assisted reading when I was guiding him through all data points on a chart instead of focusing on the relevant key insights only. This reminded me of many of my interviewees, who tend to do the same without proper training or coaching.
2. Ensure you translate the data and insights into actual implications and recommendations. Good candidates can elicit the key pieces of information from an exhibit. Excellent candidates interpret these findings in the context of the case and use them to sharpen their hypotheses, deduct implications, and plan a way forward.

Further pitfalls

Other common pitfalls to avoid include:

Common Pitfalls in Case Interview Exhibits Analysis	Description
Analyzing the chart without an objective	Lacking a clear goal when reviewing the data, leading to aimless analysis.
Speaking before thinking	Discussing data without prior reflection, lacking structure or insights.
Unclear data context	Failing to clarify the data’s scope, time period, or source, leading to incorrect conclusions.
Over-describing data points	Describing every detail on the chart without focusing on relevant insights.
Discussing non-insights	Focusing on data points that don’t influence the analysis or offer negative insights.
Repetitive insights	Finding an insight but then repeatedly discussing it without adding value.
Repeating without concluding	Not offering conclusions or action plans.
Slow exhibit analysis	Taking too long to analyze and interpret the exhibit, exceeding a concise timeframe.
Chaotic presentation	Presenting insights in a disorganized manner, lacking clear structure or signposting.
Misinterpreting units and magnitudes	Confusing or mixing up units, failing to read charts or tables correctly.
Misinterpreting data in case context	Incorrectly interpreting data, resulting in faulty case implications.
Lengthy calculations	Engaging in unnecessary detailed calculations instead of focusing on visible insights.
Ignoring correlations and dependencies	Failing to recognize important relationships between data points.
Overlooking hidden insights	Missing insights that emerge from combining multiple data points.
Neglecting footnote or source information	Overlooking details that could alter the interpretation of data.

Steer clear of these common pitfalls and you already fare better than 80% of the case interview candidates I’ve interviewed before our first coaching session where they learn the right habits.

Typical Exhibit Insights to Look Out For

Learning how to dissect case interview visuals and data table analysis can set you apart. You need to understand what to look out for.

Types of data points

Usually, you are confronted with many different data points and information on one or two exhibits. To figure out what the key insights are, group the data points on any given exhibit into three different categories:

1. Data points that are relevant for you: The key is to select the most important bits of information, usually outliers, unexpected data, or abnormalities that are relevant in the context of the case, and most striking when looking at the exhibit. Some of those insights might be generated by combining several data points.
2. Data points that are not relevant: There are always other things you could discuss, but in the interest of time, skip every data point that is not relevant for the case or your hypothesis or simply not interesting enough (e.g., a two percent drop in revenue for one particular product category is not that interesting if another product’s revenue dropped by 23%). Think 80/20.
3. Misleading data points: Not all information shown to you is insightful or important, and some might even be misleading, just to create noise and distract you. Some exhibits might contain decoys that trick you into faulty conclusions. Hence, think before you speak and do not blurt out faulty statements that come to your mind quickly and might be based on wrong assumptions.

Let’s have a look into the typical data points that are relevant for you – the first category from above.

Typical categories of insights

• Comparison: Compare different sets of data with each other, such as,
  • internal vs. external (e.g., client vs. market)
  • internal vs. internal (e.g., product A vs. product B)
  • external vs. external (e.g., competitor A vs. competitor B)
  • scenarios (e.g., supplier A vs. supplier B; option A vs. option B).
• Segmenting: Look for insights at a more granular level, do not look at averages and aggregates, for instance,
  • breakdown of a process (e.g., customer journey)
  • breakdown of financials (e.g., revenue)
  • breakdown of business segments (e.g., sales)
  • breakdown of geographic regions (e.g., growth).
• Relationships: Investigate a relationship or correlation between two or more variables:
  • positive (e.g., cost and quality)
  • negative (e.g., age and health).
• Changes and trends: Look for absolute or relative changes in one or several values over time to spot trends and trend reversals, such as,
  • financials (e.g., revenue)
  • customer data (e.g., purchasing behavior, satisfaction).

Types of insights, usually outliers

• A figure or group of figures is very small or very large compared to the others, often based on a comparison of patterns and correlations.
• A figure is very different from what you would have expected (rejects your hypothesis) or exactly what you would have expected (confirms your hypothesis).
• A figure or breakdown of figures is very different than others.
• A figure or group of figures shows high or low growth (decline) compared to the others.
• The data changes significantly at a certain point (e.g., spikes or bottoms, trend reversals).
• On average, the figures look good, however, when digging deeper into specific segments you see certain issues or deviations.

Learn how to spot those kinds of patterns quickly.

When you are given two or more charts, the key insights often come from combining the data points of both. For instance, if you are comparing checkout speed across several stores the number of cashier desks alone is not enough. You might only get to an insight if you are able to relate the number of cashier desks to things such as the size of the store, the number of customers, the number of items purchased, etc.

Train Chart Interpretation

Improving your exhibit interpretation skills for consulting can dramatically increase your chances of success. Enhance your consulting interview preparation with chart analysis by practicing with real-world examples and professionals.

Free practice

You can quickly improve your exhibit interpretation skills by applying the approach, the right communication, and the tips above to practical examples. Prepare for case interviews by analyzing charts in magazines such as The Economist or The Wall Street Journal. A quick Google search for “Chart of the day” yields thousands of results that you can use to practice and hone your chart interpretation skills. To check your insights, compare them with the text of the articles accompanying these charts. Additionally, look for online case libraries and go through university consulting club casebooks.

When practicing, follow the steps I describe above.

• Internalize the seven steps.
• Time yourself to create realistic conditions and pressure (one minute to think, one to two minutes to communicate your analysis).
• Train your eyes to find insights quickly based on outliers and abnormalities.
• Train your mind to generate implications and next steps in the context of the case.
• Become comfortable with the top-down communication of your analysis by practicing out loud, including recording yourself and critically listening to your performance.

Courses and professional coaches

For those keen on enhancing their chart analysis skills through a comprehensive approach, our dedicated course offers an invaluable resource. It’s designed with precision to cater to learners at all levels, featuring extensive discussions on a plethora of examples and equipped with 50 practice questions. These questions are not ordinary; they come with high-quality charts and data tables that meet the rigorous standards of top-tier consulting firms like McKinsey, the Boston Consulting Group, and Bain & Company. This course is the fastest and most realistic way to practice and master chart analysis, providing you with the tools and insights needed to excel in your endeavors.

Alternatively, I do offer private coaching sessions and – at the time of updating this article – have conducted more than 1,600 case interview sessions.

In addition, establish a case interview math practice routine since case math might be based – as a follow-up question – on the exhibits you receive during the interview.

How We Help You Ace MBB Interviews

We have specialized in placing people from all walks of life with different backgrounds into top consulting firms both as generalist hires as well as specialized hires and experts. As former McKinsey consultants and interview experts, we help you by

• tailoring your resume and cover letter to meet consulting firms’ highest standards
• showing you how to pass the different online assessments and tests for McKinsey, BCG, and Bain
• showing you how to ace McKinsey interviews and the PEI with our video academy
• coaching you in our 1-on-1 sessions to become an excellent case solver and impress with your fit answers (90% success rate after 5 sessions)
• preparing your math to be bulletproof for every case interview
• helping you structure creative and complex case interviews
• teaching you how to interpret charts and exhibits like a consultant
• providing you with cheat sheets and overviews for 27 industries.

Reach out to us if you have any questions! We are happy to help and offer a tailored program to help you break into consulting.

Frequently Asked Questions: Chart Interpretation

Navigating through charts and data tables in case interviews can be daunting. Here’s a FAQ to help you deepen your understanding and sharpen your exhibit interpretation skills for success in consulting case interviews.

How can I develop a hypothesis before analyzing the charts and data tables in a case interview?
Start by understanding the case’s objectives and identifying potential areas of interest or concern. Use this initial insight to frame a hypothesis that your analysis of charts and data tables will either support or refute.

Are there specific types of charts or data tables that are more prevalent in certain industries or types of case studies?
Yes, certain industries prefer specific types of data visualization. For example, financial sectors often use line charts for trend analysis, while marketing studies may rely on pie charts to illustrate market segments.

What are the best practices for managing time while interpreting exhibits during a case interview?
Quickly skim the exhibit to grasp the main idea, then focus on the most relevant data points that relate to your hypothesis. Practice a structured approach to quickly elicit insights without sacrificing thoroughness.

Can you provide examples of how misinterpreting a chart or data table has led to incorrect conclusions in real consulting projects?
Common errors include misreading the scale on graphs, overlooking footnotes that clarify data, and assuming correlation implies causation without further analysis.

How does the interpretation of exhibits differ between candidate-led and interviewer-led case interviews?
In candidate-led interviews, you choose which data to explore to support your hypothesis, while in interviewer-led cases, you’ll analyze the exhibits provided by the interviewer in line with their questions.

What are some advanced techniques for identifying interesting data points?
Look for data points that don’t fit the overall trend or pattern, question outliers, and consider the broader context of the case to determine whether the data is truly relevant.

How can candidates effectively practice exhibit interpretation outside of the context of a case interview (e.g., using real-world data)?
Engage with real-world business news, analyze the charts and data presented, and try to draw conclusions or insights as if you were preparing a consulting recommendation. Work with proper drill programs.

What role do cultural or regional differences play in the presentation and interpretation of data in case interviews across different offices of MBB firms?
From my experience, there is no difference across firms and offices. All firms work on a global scale on similar business problems, which is also reflected in the types of interviews and exhibits.

How can a candidate demonstrate their analytical skills when the data presented in the exhibit is insufficient or incomplete?
Highlight the gaps in the data, suggest ways to fill these gaps based on logical assumptions, and explain how additional information would influence your analysis.

In sum, understanding data visualization in consulting cases is pivotal for articulating compelling recommendations.

Struggling with charts and data in case interviews?

We know that mastering the art of exhibit interpretation can be daunting, but you’re not alone in this journey. If you have any questions or need further clarification, don’t hesitate to ask them below in the comment section. Your queries not only help you but also assist others facing similar challenges. Let’s navigate the complexities of case interviews together and turn obstacles into stepping stones for success.