Tests of Evidence One on One Won't Work Evidence Standards Checking Evidence Evidence Arguments

One On One Won't Work:

If the affirmative gives a piece of evidence that says A is true and the negative gives a piece of evidence that says A is false, frequently the affirmative will simply provide another piece of evidence, the negative will do the same, and the cycle goes on and on. In such cases, the judge usually marks off both sides and neither wins the issue. Time and effort has been wasted.

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Evidence Standards:

In order to correct this problem, debaters need to weigh the evidence on both sides. Like topicality standards, test for evidence demonstrate that one piece is superior to another.

• Relevance: Is the evidence supportive or related to the argument? The evidence that the debater uses is not relevant - it does not prove the tagline. (This problem is not infrequent. In a rush to find counter-evidence, many debaters just grab something and don't realize that it is irrelevant until they read it. Many opponents also miss this error because they are busy flowing and preparing for their next speech.)
• Qualifications of Source: Is the source of the evidence competent? Does the author have the educational background and experience to make the statement with authority? (Which paper is more trustworthy, The New York Times or The Inquirer? Which is trustworthier with national security, a janitor or a professional with 30 years experience?)
• Fact or Opinion: Is the evidence based upon fact or opinion? Evidence based upon personal opinion is weak. What are the facts that back up the opinion? (If one card reports that 50% of people who acquire disease X will die, and a second card states that 50% of physicians believe disease X is dangerous, which card would carry more weight? Facts, numbers, and statistics are usually more valuable than simple opinions.)
• Date of Evidence: Is the evidence recent? Have conditions changed such that the conclusion is no longer valid? Conditions in China are changing rapidly; information that's more than six months old may no longer be relevant. (If all else is equal, the most current source will carry more weight. However, be careful; there is a difference between the date the information was obtained and the date the information was published, i.e. the source is dated 1994 but the information was obtained in 1982.)
• Qualified Conclusions: Is the author's conclusion too qualified to be useful? What are the actual risk factors? 90% or 2%? (Watch for words like "may, "could," "possibly," or other qualifiers. What facts and other evidence is presented to back-up the qualified conclusion?)
• Secondary Source: How many different sources does an opponent use? Reliable evidence will have two or three sources and several different authorities. Evidence from one person or one source requires additional support.
• Biased Sources: Is the source biased? How objective is the information? What is the sources purpose for printing the information? (Obviously, the editors of a book like China: The Red Menace is biased and will only select information that supports their viewpoints. Obviously, a person who works for a company who buys cheap products from China will be biased in his approach to trade issues.)
• Controversial Sources: Are other experts in agreement with the source? Is the evidence well accepted among the source's peer group? (Instead of attacking the actual evidence card used, a debater may be able to show that a study is controversial and should be ignored. If you can find another expert who claims that the study was flawed, poorly conducted, or not accepted by experts in general, the judge will probably ignore the card.)

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Checking Evidence:

The easiest way to check evidence is for the debater to ask for it at the beginning of the CX and have his partner look for weaknesses. During the rebuttal, debaters must listen carefully - one person flows and the other person listens for evidence flaws.

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Evidence Argument:

Like all other issues, an evidence issue should have a tagline, supporting evidence (if needed), and an explanation in order to be effective.

• Affirmative violates evidence standards; their claims are primarily based upon one person's opinion.
• During the 1AC, the affirmative used Douglas Baker for 7 of 10 evidence cards. They should be able to find a variety of different sources and opinions to prove the reliability of their information.
• If the Affirmative does not correct this difficulty, they fail to meet their burden of proof and, therefore, must drop the round.

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