Data visualization sounds fancy, but it basically means charts and graphs. Consultants are good at quickly breaking down problems and telling stories with data. Graphs can be succinct: yes, “a picture tells a thousand words.”

Lots of research has been done on this topic and certainly best practices exist. Anything by Nancy Duarte, or Say it with Charts, Gene Zelazny (affiliate link) is a great place to start, but I have something even simpler.

Practice looking at lots of graphs and find things that you like, don’t like. In other words, try the food. See what tastes right to you; develop your own point of view. Some examples from the Economist and Wall Street Journal:

1. Keep it simple

• The biggest error with data visualization is clutter; trying to do too much
• Often, the best idea is to make two separate graphs, like below
• Here oil and natural gas prices trends are different enough to warrant two different graphs
• Oil-and-Gas Industry Faces a Slow Recovery From Pandemic Lows, WSJ, 1/17/2021

2. Show a trend, not a data point

• If you have enough data, show the trend, it puts your arguments in context
• SPAC, new ways to raise funds (blank check companies) boomed in 2020 at $82B
• Yes, $82B is a lot of money . . .especially compared to $13B in 2019
• Startups Going Public Via SPACs Face Fewer Limits on Promoting Stock, WSJ, 1/3/2021

3. Tell a story

• This is the meta-advice for anything business + visual
• Sometimes, it involves the relationships between two different factors
• Over the last 2 years, US car sales were steady, while inventory has dropped significantly
• Why You Might Have Trouble Getting the Refrigerator, Can of Paint or Car You Want, WSJ, 10/25/2020

4. Be consistent

• Yes, data and charts can lie and mislead. So, definitely use the same scale when comparing data
• Clearly Wikipedia’s future growth is in non-English languages
• Hindi looks like it is almost zero because it is on the same scale as English
• Also, be able to explain potential outliers. . .like. . . . Cebuano?
• Apparently, Cebuano is the #2 most spoken language in the Philippines with 20M speakers. Alarmingly 90%+ of the articles were written by bots. This is not an auspicious sign for the quality of all Wikipedia articles.
• Wikipedia’s future lies in poorer countries, Economist, 1/9/2021

5. Make the point obvious

• This is something we don’t do enough. Get to the point and make it obvious
• This graph is a little busy, but Ireland is clearly the main point (highest peak, bolded name)
• Ireland has a rocket-launch spike in Covid-19 cases. Upon reading the article, it looks like Ireland relaxed social distancing restrictions to give people a “meaningful Christmas”. uh, not really
• Ireland has one of the world’s highest covid-19 infection rates, Economist,1/15/2021

6. Use colors deliberately

• It’s an amateur move to use more colors, for no reason
• Here you can see that gas stations make great margin on everything except gas
• Great margin products = orange, gas = grey
• Groceries Prove a Pandemic Bright Spot for BP and Shell, Economist, 1/16/2021

7. Say something

• Every slide or data visualization should say something
• If the graph doesn’t answer the question, “So What?” better to throw it away, or put in appendix
• The US government spending bills keep getting wordier; the 2020 final version was 2,000+ pages
• Apparently, it’s unreadable in the time allotted before voting. One senator recently called on both the Republic and Democratic parties to “stop voting for bills they haven’t read”
• So what? 1) broken, spastic legislative process 2) perfect environment to sneak in “your appropriations”
• America’s elephantine spending bills are becoming increasingly unreadable, Economist,12/29/2020

8. Annotate as needed

• Don’t make a mess by adding data labels everywhere, but clarify key data points
• The CAPE ratio (market-wide P/E multiple) is not as inflated as the 1929 and 2001 crashes
• Also, labeling the average with a red dotted line makes sense, even though it looks like it doesn’t apply anymore . . .
• Expensive stocks do not necessarily mean a crash is close, Economist, 12/4/2020

9. Use maps

• Maps are easy. For example, Americans know where Texas is located
• The US electoral college is the strange system that allocates votes in a “winner-take-all” by state
• So, if you vote Democratic in very Republican state, your vote is essentially useless
• Therefore, voters in “swing states” like PA, FL, MI, WI, AZ, GA have a big marginal impact
• In this graph, the darker color = more likely that your individual vote would decide an election
• How America’s electoral college favours white voters, Economist, 08/15/2021

10. Add trend lines

• Best case = graph speaks for itself. However, it’s okay to nudge the audience and direct their attention
• Yes, lead the witness. No, do not mislead the witness
• When your sample size is big enough, add trend lines to show correlations
• When looking at GDP/person, the wealthier countries tend to believe in science and doctors
• In contrast, the wealthier the country, the less likely you believe in vaccines. Fascinating and disturbing
• Conspiracy theories about covid-19 vaccines may prevent herd immunity, Economist, 8/29/2020

11. Delineate history from forecast

• Caveat: data can mislead (think: Mark Twain quote, “lies, damn lies, and statistics”)
• When you’re showing a forecast, don’t forget to label it differently
• Here the years 2020-2024 are a forecast; noted below and in a lighter color blue
• Covid-19’s Blow to Business Travel Is Expected to Last for Years, WSJ, 1/17/2021

12. Show the data in multiple ways

• Yes, there are many different ways to analyze the same set of data
• While you don’t want to bore the reader, sometimes those different “cuts” are useful to see
• Polyethylene (plastic) demand varied by sector and by region
• Lots of plastic demand in healthcare and packaging (makes sense) in 2020; in 2021, demand growth will be in Asia
• Firms Like Dow Bet Billions on Plastics. Now There’s a Glut, WSJ, 10/15/2020

13. Label the graph well

• If you are showing data that requires a little explanation, make a graph title
• The Chinese economy has made remarkable gains over the last 20 years. Looks like China is the top merchandise trading partner with 64 countries, while the US is the #1 speed-dial position for only 38 countries
• How to deal with China, Economist, 1/9/2021

14. Use two graphs, not one

• There is nothing wrong with making multiple graphs and putting them next to each other
• See this side-by-side comparison of managed money; active going down, passive going up
• Apparently, there is $100 trillion in managed assets with increasing consolidation by the big names
• The money doctors, Economist, 11/12/2020

15. If you must have two axes, label them clearly

• Generally, I am not a fan of double axes because it has the potential to confuse the reader
• If you’re going to show two different things, label them in different color; red vs. blue
• Good job China; bringing 800M+ people out of extreme poverty
• Extreme poverty is history in China, officials say, Economist, 1/2/2021

16. Careful how you “bucket” the data

• Consulting is all about putting things into buckets
• Here assets under management (AUM) is categorized by region, with the exception of Japan
• Question: Why is Japan grouped with Australia and not Asia?
• The Shanghai Open, Economist, 11/12/2020

17. Pair up charts

• As a consultant, nothing is better that proactively answering a client’s question before they get a chance to ask
• The first graph is of IPO proceeds raised by Chinese companies; 2020 was the highest at $110B+
• The second graph answers the question of how many US listings (ADR) over the same time period
• Why Chinese firms still flock to American stock exchanges, 10/17/2021

18. Don’t use pie charts

• I remember when a senior manager once told me that pie charts weren’t that useful
• Now, I completely agree now. . .trend lines are WAY better because they provide context
• See market share of beverage over time; what’s up Pepsi?
• How Donald Kendall, as PepsiCo’s boss, sparked the cola wars, 09/26/2020

19. Surprise the reader

• Be creative with your data sets and comparison
• The Midwest United States is a vibrant (often overlooked) part of the economy
• Comparing it to countries (i.e., Japan, Germany) helps to deliver the message
• The best-run cities of America’s Midwest offer lessons in recovery, 7/25/2020

20. Put things in the appendix

• This is a timeline of Google, which is an eyeful. Probably deserves to be in the appendix, not the main presentation
• It doesn’t convincingly answer the question “So What?”
• Google’s problems are bigger than just the antitrust case, Economist, 7/30/2020

21. Sometimes a table is better

• A mentor of mine always says that tables are underrated. I agree completely
• If you are showing a bunch of numbers (see the graphic below of 32 numbers), why not just put it in a table
• Also, I had no idea that Thailand has so many billionaires
• South-East Asian tycoons’ high-wire act, Economist, 5/8/2020

What other tips do you have for data visualization?