Supporting your Central Idea: Data and Statistics

The right data and statistics can make your argument watertight; the wrong ones can drown your story. A savvy speaker can use data and statistics to illustrate and prove a point without overwhelming the audience with too much qualitative information. You need to know which kinds of data will best support your claims, how to make your data comprehensible to an audience, and how to become a more informed consumer of data yourself so that you can avoid taking in and passing along bad statistics.

Data

Data: that is, facts and statistics, provide credibility and clarity in a speech, giving concrete, specific numbers or results about the extent or impact of a particular situation. Compare the effect of the following two statements:

1. A lot of children in America are hungry.
2. A 2018 report from Food Research & Action Center states that more than 18% of American households, that’s nearly one in five, have food hardship where they haven’t had enough money to buy food.

The first statement is vague and easily forgettable. The second statement adds credibility and specificity to the extent of childhood hunger. Combining that statistic “more than 18%” with “nearly one in five” re-emphasizes the extent of the problem and makes it more relatable to an audience.

In addition to numerical statistics, findings from research can add depth and meaning to your speech. The speaker in this five-minute speech on “The Benefits of Doodling” includes a brief description of a study to support her first main point about the impact of doodling on memory retention.

You can view the transcript for “Doodling” here (opens in new window).

Here is the video with accurate captions: Doodling (opens in new window).

In the following speech, statistician and mathematician Talithia Williams talks about how collecting data on your health can make you the authority on your own body, and give you a new sense of agency and control.

You can view the transcript for “Show me the data — becoming an expert in yourself: Talithia Williams at TEDxClaremontColleges” here (opens in new window).

Using Data and Statistics in Your Speech

Using data and statistics in public speaking can be a powerful tool, providing a quantitative, objective, and persuasive platform on which to base an argument, prove a claim, or support an idea. While data and statistics add credibility, specificity, and depth to a speech, they need to be integrated thoughtfully. Review the following eight suggestions:

One

Too many statistics and numbers can be overwhelming and boring to audiences, so use them only as needed.

Two

Translate complex or overly-technical ideas into clear language.

Three

Round large or complex numbers.

Four

Use relatable comparisons.

For example, the speaker in the doodling video compared the memory retention from doodling to the grade on a test. Or, as another example, rather than stating “The Great Pacific Garbage Patch is 1.6 million square kilometers,” a number that most audiences can’t easily understand, try something like “The Great Pacific Garbage Patch is twice the size of the state of Texas or three times the size of France.”

Five

Consider using statistics and research as initial supporting evidence for each main point. Also, a particularly shocking or surprising statistic might be used as a hook in a speech’s introduction.

Six

Use reputable sources for the statistics you present in your speech such as government websites, academic institutions and reputable research organizations, and policy/research think tanks. Also realize that even though sources may be reputable, you need to examine the statistics carefully when drawing conclusions to present.  In the following video, Lilit Tarverdyan, a student at the American University of Armenia, illustrates this idea as well as shows how to use a statistic as an introductory hook.

You can view the the transcript for “What are the consequences of misleading statistics? | Lilit Tarverdyan | TEDxAUA” here (opens in new window).

Here is the video with accurate captions: What are the consequences of misleading statistics? | Lilit Tarverdvan | TEDxAUA (opens in new window).

Seven

Put data and statistics into context for your audience. As Chip and Dan Heath state, “Statistics are rarely meaningful in and of themselves. Statistics will, and should, almost always be used to illustrate a relationship. It’s more important for people to remember the relationship than the number.”^[1] Graphs, tables, and maps can be used to communicate the numbers, but then the numbers need to be put into context to make the message stick.

In their book, the Heaths give several good examples of others who have done this. For example, they introduce us to Geoff Ainscow, one of the leaders of the Beyond War movement in the 1980s.

“Ainscow gave talks trying to raise awareness of the dangers of nuclear weapons. He wanted to show that the U.S. and the USSR possessed weapons capable of destroying the earth several times over. But simply quoting figures of nuclear weapons stockpiles was not a way to make the message stick. So, after setting the scene, Ainscow would take a BB pellet and drop it into a steel bucket where it would make a loud noise. The pellet represented the bomb that was dropped on Hiroshima. Ainscow would then describe the devastation at Hiroshima. Next, he would take 10 pellets and drop them in the bucket where they made 10 times as much noise. They represented the nuclear firepower on a single nuclear submarine. Finally, he poured 5,000 pellets into the bucket, one for each nuclear warhead in the world. When the noise finally subsided, his audience sat in dead silence.”

That is how you put statistics into context.

Eight

Show statistics with visual aids, including simple charts or graphs or objects might help your audience understand and retain the information. However, when presenting graphs, make sure that the key points are highlighted and the graphs are not misleading as far as the values presented.

Graphs and graphics can simplify large data sets and make an argument more compelling and memorable. However, they can also distort the real significance of the data through the manipulation of scale and context or the omission of key data points. Make sure to look carefully at any graphs or graphics you might include in your presentation!

In the two videos that follow, you’ll see how graphs and maps can be misleading.

Lea Gaslowitz talks about how graphs can be misleading.

You can view the transcript for “How to spot a misleading graph – Lea Gaslowitz” here (opens in new window).

This video shows how the map of electoral votes fails to illustrate – and even conceals – the way electoral votes actually work, and offers ways to think more creatively about visual presentations.

You can view the transcript for “The bad map we see every presidential election” here (opens in new window).

The key to presenting effective tables, graphs, or maps is to ensure they are easy to understand and clearly linked to the message. Ensure that you provide all the necessary information required to understand what the data is showing. The table, graph, or map should be able to stand alone.

Tables, graphs, and maps should relate directly to the argument, support statements made in the text, summarize relevant sections of the data analysis, and be clearly labeled.

Table Checklist

• Use a descriptive title for each table.
• Label every column.
• Provide a source if appropriate.
• Minimize memory load by removing unnecessary data and minimizing decimal places.
• Use clustering and patterns to highlight important relationships.
• Use white space to effect.
• Order data meaningfully (e.g., rank highest to lowest).
• Use a consistent format for each table.
• Do not present too much data in tables. Large expanses of figures can be daunting for an audience, and can obscure your message.

Graph Checklist

• Use a clear, descriptive title.
• Choose the appropriate graph for your message, avoid using 3D graphs as they can obscure information.
• Decide which variable goes on which axis, and what scale is most appropriate.
• If there is more than one data series displayed, always include a legend, preferably within the area of the graph.
• All relevant labels should be included.
• Colors can help differentiate; however, know what is appropriate for the medium you’re using.
• Provide the source of data you’ve used for the graph.
• For readability, it’s generally a good rule of thumb to make the y-axis (the vertical or left-hand line) three-quarters the size of the x-axis (the horizontal or bottom line).

What not to do when using Data and Statistics

Whenever you present statistics, it’s important to examine them with a careful and critical eye. Statistics can tell a powerful story, but bad statistics can mislead your audience, weaken your argument, and damage your credibility. Don’t do the following five things.

1. Don’t manipulate data to jump to a false conclusion; always be sure to present accurate information. For example, just because an increase in home prices happened after the last lunar eclipse doesn’t mean that you can argue that one caused the other.  Watch out for false conclusions both in the data you find and in your own use of data and statistics.
2. Don’t discard important information that’s unfavorable to your central idea.  If it’s valid information, make sure to address it and then show additional information that supports your central idea.
3. Don’t use data that is a result of bad surveys or loaded questions.  For example, surveys that ask questions such as “Do you support the attempt by the U.S. to bring freedom and democracy to other places in the world?” or “Do you support the unprovoked military action by the USA?” will likely result in data skewed in different directions, although they are both polling about support for a war. A better way of wording the question could be, “What is your view about the current U.S. military action abroad?” The point should be that the person being asked has no way of guessing from the wording what the questioner might want to hear.
4. Don’t use data that’s overgeneralized, and don’t overgeneralize yourself based on data you find.  If you only consult one source offering one particular viewpoint on a controversial subject for a persuasive speech, and then imply that the source’s conclusion is true for everyone, your audience will not view you as a credible speaker, since you have overgeneralized.
5. Don’t use data based on a biased sample. For instance, consider a political poll collected through calls to cell phones and not land lines.  Although landline use is diminishing, a poll conducted only through calls to cell phones might exclude large segments of the population in rural areas as well as older citizens.

The following video blends using data with the concepts of storytelling, effectively explaining how to use data in context.  The video’s information touches on all three ways of supporting your central idea: support through people, data/statistics, and research.

Here is the video with accurate captions and a transcript: Data Storytelling Basics (in 3 Steps): How to Communicate Data and Numbers (opens in new window).