Everybody gets so much information all day long that they lose their common sense.
Gertrude Stein
We have talked about sources of data and information and how to sort out the wheat from the chaff, focusing on the information that is important to you.
Now that you have done that and you are clear about what is going on, the next step is to be able to explain it to everybody else. You need to present the data clearly.
The question you need to address is, “How do I show the information in a way that tells a clear story? A way that is easy to understand and makes a compelling point?”
What is Your Compelling Point?
In 2009 the Local Government Association released a list of 200 words and phrases. Words that councils should avoid as they are unclear. Included on the list were the following terms and their recommended replacements:
- Action – Do
- Core message – Main point
- Functionality – Use
- Outcome focused output – Result
- Potentialities – Chances
- Procure – Buy
- Slippage – Delay
- Transformational – Change
One City Council rose to the challenge, slashing the statement:
Individual Chief Officers have the delegated authority to appoint employees on a temporary basis to provide cover for staff absences, to cater for peaks in workload and to deal with any tasks which may arise which are outside of normal workload of the department. Such approvals to be subject to there being budgetary provision available and a check being made with the Personnel and Training Division to ascertain whether the cover could be provided by either a redeployment or a secondment.
Leeds City Council
Down to a simple:
If they are required, money is available, and the job can’t be done by another member of staff, chief officers may hire temporary workers.
Leeds City Council
You might be thinking, what has that got to do with data presentation?
The answer is quite simple. It is about clear communication. Every chart or table that you draw should give a clear message. Have a look through your old presentations and ask yourself one question.
“What exactly is my point?”
If you aren’t clear about the point you are trying to make, don’t even think of drawing a graph.
Choose Your Weapon
Once you know your point, it is time to choose the method that communicates that point best.
Data tables
Accountants love data tables; I think all those numbers must give them a sense of security. A good first question is should I use a table or a graph?
Tables work when:
- It is necessary to look up each value.
- The precise value is essential.
- There are multiple units of measure.
If you are in a hospital and the doctor is looking up the dose of a drug he is about to administer, you’d hope he is using a table of data to do it.
If the message is about the shape of the data or showing a relationship, a graph is better. A picture tells a thousand words. Look at the information on military spending in the table and chart below. Which method gets the message over most succinctly?
If you think a graph would work best, the next question is which one to use. The question isn’t made easier because the different software providers (Microsoft, Apple, Google, Minitab, etc.) are in mortal combat over market share. They want to prove that their software is the best by providing you with every chart, colour, shape, and size combination you could ever want. But that isn’t helpful as it is easy to become bamboozled with choice.
Except for extreme cases, there are only four types of graph you need:
Pie charts
The simplest type of chart. Pie charts help display portions of a whole. For E.g. how do employees spend their time at work? Pie charts are simple and easy to understand.
The pie chart has two drawbacks:
- If there are more than five different slices, they become hard to read.
- If the size of the components is similar, it isn’t easy to see which is the largest.
Only use a pie chart if the data you want to show is simple.
Line charts
Use a line chart to show how something varies over time — to show a trend. Usually, time is shown along the horizontal axis. Show the other unit along the vertical axis. The resulting line indicates change over time.
When using line charts, be clear about the vertical axis’s scale; otherwise, it can confuse. The two lines on the chart below show precisely the same data but on different scales. Changing the scale can give a very different message. Is performance stable or all over the place?
Bar charts
It would be best to use bar charts to show data from different categories. E.g. volume of calls by call reason or number of orders by product type. A line chart implies a relationship between points as it moves across the page — E.g. sales volumes over time. Bar charts show different items which are not related — E.g. sales of different products. Use a bar chart instead of a pie chart if you have six or more categories to display.
Ordering items from largest to smallest is an excellent way to show relative importance.
Scatter plots
Use scatter plots to show the relationship between two variables. Perhaps people’s height and weight, or price and number of sales.
If the points show a pattern, then there is a relationship; if they don’t, it is safe to assume there isn’t. Scatter plots can be helpful when trying to determine cause and effect. For example, a scatter plot will show if the size of a sales order determines the time it takes to process.
It is best not to show more than one relationship on a scatter plot at a time. If you do, you will see dots before your eyes.
Label your chart
If you want to ensure that your audience understands the point you want your chart to make, write that in the chart title.
Chart Type | Bad Title | Good Title |
---|---|---|
Pie | Workload | Complaints Cause Nearly Half of our Workload |
Line | Complaints | The Volume of Complaints has Remained Constant Over Time |
Bar | Complaint Reasons | Our Biggest Driver of Complaints is Late Delivery |
Scatter | Late Delivery vs Order Size | The Bigger the Order Size, the Later we Deliver |
Be as Dull as You Like, Be Duller
You wouldn’t have a serious conversation with Motörhead blaring away in the background. Not unless you were 16. The noise is disruptive; it gets in the way. Similarly, it is just as hard to hold down a conversation with a couple of kids screaming in the background. I have tried. The conversation gets diluted; communication doesn’t happen. It is hard to get your message over when you are distracted by something else.
The second related point is that studies have shown that most people have an attention span of about 8 seconds. You have 8 seconds to get your point over before your audience’s mind has drifted off elsewhere.
If we only have 8 seconds and distractions get in the way of effective communication, why do we insist on adding lines, points, annotations and all sorts of other stuff to the charts we draw? Edward Tufte has a nice turn of phrase for this; he calls it “Chart Junk”.
The purpose of a chart is to communicate an idea or point. You are just adding noise if you doll it up with 3D and colour, axis lines, and fancy graphics. You waste those valuable 8 seconds on unnecessary details that don’t help you get your argument over. Stick to the point and remember that less is more. The only exception is to add axis labels and scales (just like your teacher told you to when you were 10.)
What is the point that this chart is trying to make?
Homework
Review the management information that you have and ask yourself:
- What is the point that each chart is making? Is the message clear from the moment you look at it? If it isn’t, work out what that message is, and write it at the top of the chart.
- Look at the data you have. Work out which of the data sets you have is critical to supporting the message. Remove everything else.
- Determine which of the basic chart formats is the best (clearest) way to reinforce your point.
- Where you want to draw out a specific action or issue, state it at the bottom of the page.
- Remember, this isn’t an exercise in page optimisation; it is an exercise in communication. It doesn’t have to look pretty or managerial; it does have to look clear.
In the next lesson, we will talk about how you use management information. It is useless if it doesn’t drive management action.
Thank you for reading.
I’m not dumb. I just have a command of thoroughly useless information.
Bill Waterson
Related posts:
- How to make a point: What can a tax collector teach you about getting your message over?
- Avoiding death by PowerPoint: How to make assertions and use evidence.
- If you must write on your slides: The golden rule.
Across the web:
- Good examples of bad charts: How not to do it.
- The secret structure of great talks: Nancy Duarte on the Ted stage.
- Data Visualisation: Edward Tufte’s keynote speech on youtube, only for the hardcore.
Further reading:
Gene Zelazny was the Director of Visual Communication at McKinsey and Co. His book is a simple, practical guide to chart drawing dos and don’ts. He is crystal clear on what to say and how to say it.
Post Script
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