Use Statistics to Quantify Your Ideas
The main value of statistics is to give your ideas numerical precision. This can be especially important when you are trying to document the existence of a problem. Examples can bring the problem alive and dramatize it in per- sonal terms, but your listeners may still wonder how many people the prob- lem actually affects. In such a situation, you should turn to statistics. Research has shown that the impact of examples is enhanced when they are combined with statistics that show the examples to be typical. 8
Suppose you are talking about the need for college students to avoid credit-card debt. Part of your speech deals with the large amount of debt the typical college student faces by the time he or she graduates. You give an example, you personalize the subject, you provide many details, as follows:
Travis Blake left college a changed person. Not only had he earned his degree, but he had racked up almost $4,000 in credit-card debt. Travis was sure he would be able to pay off his debt once he got a full-time job. But when he received his first paycheck, he found that after paying his taxes and living expenses, he could make only the minimum monthly payment on his credit cards. Rather than getting rid of his debt, he would be paying it off for years.
Confronted with this example, a listener might think, “Poor Travis. But I’m not going to end up in his spot because I don’t plan to leave college with a lot of credit-card debt.” Anticipating just such a response, a sharp speaker would include figures to quantify the extent of credit-card debt among college students in general:
According to an article last month in USA Today , the average credit-card debt of a graduating college student is $3,100, and new graduates spend almost 25 percent of their income on debt payments. If someone makes only the min- imum monthly payment on his or her credit cards—which is what most people do—they will rack up more than $4,073 in interest charges alone before paying off their original $3,100 debt. Perhaps this explains why in the past few years Luc06732_ch08_140-163.indd Page 151 8/25/11 9:21 PM user-f494
Luc06732_ch08_140-163.indd Page 151 8/25/11 9:21 PM user-f494 /202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles/202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles
www.freebookslides.com
152 CHAPTER 8 Supporting Your Ideas
the number of people under 25 filing for bankruptcy has increased by more than 50 percent.
Now the audience is much more likely to agree that they need to keep a closer eye on their credit-card balance.
Use Statistics Sparingly
As helpful as statistics can be, nothing puts an audience to sleep faster than a speech cluttered with numbers from beginning to end. Insert statistics only when they are needed, and then make sure they are easy to grasp. Even the most attentive listener would have trouble sorting out this barrage of figures:
According to the World Factbook, life expectancy in the United States ranks 50th in the world. The United States ranks 47th in the world in infant mortality.
France ranks 9th. Americans spend more each year on health care than any other nation—$2.5 trillion dollars, or 17.6 percent of gross domestic product—yet the World Health Organization ranks the U.S. health care system 37th in overall per- formance among member nations.
Instead of drowning your audience in a sea of statistics, use only those that are most important. For example:
According to the World Factbook, the United States has one of the lowest life expectancies among industrialized nations—plus one of the highest rates of infant mortality. Even though we spend more on health care than any other nation, the World Health Organization ranks 36 nations ahead of us on the overall per- formance of our health care system.
This second statement makes the same point as the first statement, but now the ideas are not lost in a torrent of numbers.
Identify the Sources of Your Statistics
As we have seen, figures are easy to manipulate. This is why careful listeners keep an ear out for the sources of a speaker’s statistics. One student learned this by experience. In a speech titled “Tax Reform: Fact Versus Fiction,” he claimed that the wealthiest 1 percent of U.S. taxpayers pay 38 percent of federal income taxes, even though they account for only 20 percent of all earned income. He also noted that the wealthiest 25 percent of Americans pay 86 percent of federal income taxes. These are startling statistics. But because the student did not say where he got them, his classmates were sure he must be wrong.
As it turned out, the figures were quite reliable. They had come from a study by the Internal Revenue Service reported in the New York Times. If the speaker had mentioned the source in his speech, he would have been more successful. 9 Explain Your Statistics
Statistics don’t speak for themselves. They need to be interpreted and related to your listeners. Notice how effectively one student did this in a speech about Chinese culture in the United States:
Food is another aspect of Chinese culture that has become part of American life. According to Jennifer Lee’s new book, The Fortune Cookie Chronicles, there Luc06732_ch08_140-163.indd Page 152 8/9/11 9:20 AM user-f494
Luc06732_ch08_140-163.indd Page 152 8/9/11 9:20 AM user-f494 /202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles/202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles
www.freebookslides.com
Statistics 153 are some 43,000 Chinese restaurants in the United States. That’s more than all
the McDonalds, Burger Kings, and KFCs combined.
Explaining what statistics mean is particularly important when you deal with large numbers, since they are hard to visualize. How, for example, can we comprehend the size of the U.S. national debt, which is projected to hit
$20 billion by 2015? We could explain that a trillion is a thousand billion and a billion is a thousand million. But millions and billions are almost as hard to visualize as trillions. Suppose, instead, we translate the huge numbers into terms a listener can relate to. Here is one speaker’s solution:
How much money is a trillion dollars? Think of it this way. If you had $1 million and spent it at the rate of $1,000 a day, you would run out of money in less than three years. If you had $1 billion and spent it at the rate of $1,000 a day, you would not run out of money for almost 3,000 years. And if you had $1 trillion and spent it at the rate of $1,000 a day, you wouldn’t run out of money for nearly 3 million years!
Whenever you use statistics in your speeches, think of how you can make them meaningful to your audience. Rather than simply reciting figures about, say, the continuing destruction of the world’s rainforests, find a way to bring those figures home to your audience. You might say, as did one speaker:
According to the Rainforest Action Network, rainforest is disappearing at an alarming rate. Within the next second, we will lose an area of rainforest equal to two football fields. Within the next fifteen minutes, an area the size of this cam- pus will be erased. By this time tomorrow, 214,000 acres, an area equivalent to the size of New York City, will be gone forever.
View this excerpt from “The Rainforests: Nature’s Pharmacy” in the online Media Library for this chapter (Video 8.6).
checklist
Using Statistics
YES NO
1. Do I use statistics to quantify my ideas?
2. Are my statistics representative of what they purport to measure?
3. Are my statistics from reliable sources?
4. Do I cite the sources of my statistics?
5. Do I use statistical measures (mean, median, mode) correctly?
6. Do I round off complicated statistics?
7. Do I use visual aids to clarify statistical trends?
8. Do I explain my statistics and relate them to the audience?
Luc06732_ch08_140-163.indd Page 153 8/25/11 9:21 PM user-f494
Luc06732_ch08_140-163.indd Page 153 8/25/11 9:21 PM user-f494 /202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles/202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles
www.freebookslides.com
154 CHAPTER 8 Supporting Your Ideas
Be creative in thinking of ways to relate your statistics to your audience.
This is probably the single most important step you can take to make statis- tics work in your speeches.
Round Off Complicated Statistics
Mount Kilimanjaro is 19,341 feet high; the official world land speed record is 763.065 miles per hour; the population of Libya is 6,461,454 people; the moon is 238,855 miles from earth.
These are intriguing figures, but they are too complicated to be readily understood by listeners. Unless there is an important reason to give exact numbers, you should round off most statistics. You might say that Mount Kilimanjaro is 19,300 feet high; the world land speed record is 763 miles per hour; the population of Libya is more than 6 million; and the moon is 239,000 miles from earth.
Use Visual Aids to Clarify Statistical Trends
Visual aids can save you a lot of time, as well as make your statistics easier to comprehend. Suppose you are discussing the declining purchasing power of the U.S. dollar over the past century. You could start by explaining that in 1913, before the United States entered World War I, the dollar was at an all- time high. It fell off during the war, but it regained value during the 1920s, and in 1933 it stood at 80 cents of its 1913 value. Beginning in the 1940s, however, the dollar started a long decline that has yet to end. By 2011, it was worth less than four cents compared to 1913.
These are interesting statistics, and you could build a good speech around them. But strung together in a few sentences they are hard to digest. Figure 8.1 shows how much more clearly the points can be made with a simple graph. We shall discuss visual aids in detail in Chapter 14. For the moment, keep in mind that they can be helpful in presenting statistical information.
Purchasing Power of the Dollar
$0.00
$0.20
$0.40
$0.60
$0.80
$1.00 January 1913 = $1.00
1913 1923 1933 1943 1953 1963 1973 1983 1993 2003 2013 January 1933 = 80 cents
June 2011 = 3.9 cents FIGURE 8.1
Luc06732_ch08_140-163.indd Page 154 8/9/11 9:20 AM user-f494
Luc06732_ch08_140-163.indd Page 154 8/9/11 9:20 AM user-f494 /202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles/202/MHSF283/Luc06732_disk1of1/0073406732/Luc06732_pagefiles
www.freebookslides.com
Testimony 155
Testimony
Imagine that you are talking with a friend about the classes you plan to take next term. You are not sure whether to sign up for Psychology 230 or Account- ing 181. Both are requirements; both meet at the same time of day. Your friend says, “I took those classes last year. They’re both good, but Professor Hassam was excellent in Psych 230. If she’s teaching it next term, I’d take it for sure.” You check the timetable and find that Professor Hassam is indeed slated for Psychology 230. You sign up for her course.
As this story illustrates, we are often influenced by the testimony of other people. Just as you are likely to be swayed by your friend’s recommendation about which class to take, so audiences tend to respect the opinions of people who have special knowledge or experience on the topic at hand. By quoting or paraphrasing such people, you can give your ideas greater strength and impact.
The two major kinds of testimony are expert testimony and peer testimony.