The Ferguson Center
for Public Speaking
Claire E. Deal
Associate Professor of Rhetoric
Morton Hall, 114
Researching Your Topic
Preparing & Delivering Oral Presentations
Researching Your Topic
The second step in preparing your presentation is gathering evidence in support of your thesis. In most cases, you will need to research your topic and then, based on your audience analysis, decide what research material will be most effective in your presentation.
Incorporating Evidence/Supporting Material in your speech may serve several purposes, as follows.
- to explain :When a speaker needs to elaborate on a point, he or she may employ a definition, an example, an analogy, or audio-visual aid
- to prove: A speaker may include expert testimony, statistics, facts, graphs, and charts as evidence to prove a point.
- to increase credibility: "Doing your research" adds credibility to your role as a speaker.
- to motivate: Vivid examples, impressive statistics or powerful analogies can be used to arouse emotions and motivate your audience.
What are the types of supporting material?
1. Definition: Statements used to clarify the meaning of an unfamiliar term
2. Description: Descriptions have the potential to create understanding and arouse interest through the vivid and exact use of language.
3. Analogy: Statements that infer a similarity between two concepts or things A figurative analogy compares two basically dissimilar things which happen to have one observable characteristic in common. Metaphors and similes fall under this type. A literal analogy compares two very similar objects such as two people, two cities, or two countries. The similarity is based on a large number of features instead of only one.
4. Examples/ Illustration: Detailed narratives used to explain or clarify ideas
5. Statistics: Use of figures and numerical data
Consider the following when using statistics: Always check figures for accuracy; when presenting, use comparison and contrast to interpret statistics; round off large or complicated numbers when the general meaning will not be lost; present your figures in terms the audience can understand.
6. Testimony: The use of another person's words to support the speaker's ideas. Expert testimony is most effective.
How do I know if my evidence is solid?
Check the validity of facts by looking at the following tests:
Is the fact directly observable? Is the fact generally accepted as fact? Do other facts or expert opinion support the fact? Is the alleged fact consistent with other known facts?
Check the validity of statistics by looking at the following tests:
Are the statistics based on an adequate and representative sample? Are the units of comparison comparable? Is the use of statistics meaningful? Is there a standard to measure against? If so, what is it? Are percentages misleading? Do not try to confuse your audience by playing with the numbers. This is unethical and may cause the audience to lose faith in the speaker.
Ask yourself these questions concerning opinions or testimony:
Expert opinion -- Is the person truly an expert? Is the person an expert in the field in which he or she is giving testimony? Are the expert's opinions shared by other experts? Is the expert unbiased?
Lay opinion -- What are the facts? Are witnesses consistent in their reporting of facts? Is other evidence available?
Ready to research? The reference librarians at the College Library will be happy to offer assistance as you begin your search.