In this conversation, Mike discusses best practices on using charts.
Geetesh: Among all graphic types, what makes charts stand apart — and what are your top suggestions for users who want to add charts on their slides?
Mike: There are two reasons quantitative charts rock! (I am referring specifically to area charts, bar charts, bubble charts, candlestick charts, circle charts, Gantt charts, line charts, pie or segment charts, and point charts.)
- Quantitative charts provide proof. Numbers validate your assertions. Making a bold claim without evidence is more opinion than fact. You’ll run the risk of losing credibility if you don’t provide evidence.
- Quantitative charts make it easy to analyze large amounts of data. Compared to raw data or tables, charts help us identify trends and make quick comparisons. You can use numbers alone to explain how your company will save your client more money than your competition; however, a bar chart or a line chart shows the difference and has greater impact. Below are two charts. One shows an overload of data in a spreadsheet, and the other is a simplified bar chart with graphic elements that reflect the subject matter (lumber used for the bars). The bar chart targets specific data and visually depicts the most important facts the author wants the audience to understand. Which is more memorable and easier to read?
When adding charts to slides, remember the following best practices:
- Include relevant data only. Do not add information that has no relevance to the purpose of your chart. For example, if we are analyzing trends for the last 10 years, anything beyond that timeframe interferes with the chart’s ability to help the audience understand your point and goal.
- Consolidate data if your goal is to persuade. Make it easy for your audience to see the trend that supports your claim. Make it obvious.
- Choose the right chart. Each quantitative chart presents information differently. For example, if your goal is to quickly compare data points, a bar chart might succeed where a pie chart may fail.
Geetesh: Is there any scenario in which users may be better off using graphics other than charts on their slides — or a different type of chart other than the usual bar, column, and pie charts?
Mike:The type of chart or graphic chosen depends upon the primary objective (the purpose of the slide), audience, and subject matter. For example, if you intend to sell a fleet of hybrid cars to a rental car company, you may choose to use a gauge graphic (gas gauge) to compare your car’s fuel economy with another leading hybrid car’s capacity. In this case the graphic type—a gauge graphic (shown below)——stands out, is consistent with the subject matter, and makes a memorable point.
Charts are great for distilling down data, but due to their ubiquity they are difficult to remember. We tend to remember things that stand out. Combine your charts with other graphic types or switch to another graphic type to improve your success rate. (Nigel Holmes does a fantastic job of creating unique charts that convey quantitative information, yet are highly memorable.) There are many different graphic types and an unlimited number of options to combine graphics. For example, you could use a bar chart to show an increase in sales. However, an interesting (and memorable) way may be to use a stair graphic with each step representing a year and its revenue with the top step being the goal set for your organization. To select the right graphic I recommend downloading my free Graphics Cheat Sheet (links to a PDF). It helps me choose the right graphic for the right need.
See Also: The Powerful Presentation Graphics Guarantee by Mike Parkinson