Types of Evidence in Persuasive/Argument
Papers
Support your position or thesis with evidence. Remember that your evidence must appeal to reason.
The following are different ways to support your argument:
Facts
Statistics
Quotes
Examples
1. Using facts is a powerful means of convincing. Facts can come from your reading, observation, or
personal experience. Facts cannot be disputed. This makes them a strong form of evidence. Note: Do
not confuse facts with truths. A "truth" is an idea believed by many people, but it cannot be proven. For
example:
• Grass is green.
• All cats are animals.
• Jumping out of airplanes without a parachute is hazardous.
However, facts can be interpreted or presented in skewed ways, which may result in skewed or
erroneous conclusions. Personal opinions (such as “Dustin Hoffman is the best actor who has ever lived”)
are never facts, they are claims. For example...
• Grass is green. (in the winter?)
• Stalin was a famous man, loved by many people.
• It's a fact that the French are smelly and snobbish.
2. Using statistics can provide excellent support for your argument. Arguments employing amounts and
numbers are concrete and therefore support claims because they use logic and facts. Be sure your
statistics come from good sources, which you will cite. Examples:
• Over 61% of Americans are overweight.
• Unemployment in Illinois is at 5%.
• During each game, Sean Hill of the NY Islanders spent an average of 20:09 minutes on the ice.
3. Using quotes from leading experts or authorities in their fields will support your position—this is a
logical appeal and is accepted by other academics as a good way to back up your claims.
• Dr. Kenneth P. Moritsugu, U.S. Surgeon General, described long term problems associated with
underage drinking: “Research shows that young people who start drinking before the age of 15
are five times more likely to have alcohol-related problems later in life.”
• Samantha King, a noted forensic specialist, stated that DNA evidence is usually indisputable.
It is EXTREMELY important to make sure that the authoritative information you choose is actually
accurate and relevant to your point. Sometimes, so-called authorities are not what they seem or
information is misleading.
• My two friends in Florida think that Miami’s a better place to visit than Chicago. (Note: these are
biased sources.)
• My grandmother, who has property worth over $2 million, believes that estate tax laws need
overhauling. (Note: she’s probably not an expert in tax law, and she has a vested interest.)
• Movie critic Eleanor Lyttle writes that Star Wars Revenge of the Sith is “wondrous” and “a mustsee.”
(Note: the actual quotation read: “Revenge of the Sith is a horrific film. It is a wondrous
waste, but it is a must-see if you want to understand what a truly bad move looks like.” In this
case, obviously, the quotations are used out of context.)
• Dr. Petrelli endorses energy drinks to boost metabolism. (Note: who is Dr. Petrelli?)
4. Using examples or anecdotes from your own experience can enhance your meaning and also engage
the reader. Personal examples make your ideas concrete. These real-life examples allow a reader to
relate to the issues personally.
• For many years, my best friend’s husband beat her—the police did nothing about it; therefore,
we need better laws so domestic abusers can be punished more stringently.
• After living in Iceland for a decade, I can honestly say that the people are kind and warm.
Source Credibility Dimensions in Marketing
Communication – A Generalized Solution
Martin Eisend1
Abstract
The purpose of this study is to examine whether a generalized conceptualization of
credibility of various sources in marketing communication exists. In the survey, respondents
are required to rate source credibility by applying items gathered from previous
studies. To overcome inconsistencies and weaknesses of previous factor model studies,
a rigorous analysis of the source credibility concept based on an extraction of a series of
measurements is performed. Furthermore, an analysis procedure with various steps in
order to ensure reliability and validity is applied to the data. The selected procedure led
to a consistent and integrative solution of three highly discriminant main dimensions of
source credibility in marketing communication. The three dimensions can be referred to
as the inclination toward truth, the potential of truth and the presentation. Findings are
discussed and methodological, theoretical and managerial implications are highlighted