How Good is the Evidence: Intuition, Appeals to Authority, and Testimonials?

COSCI 58 Chapter 8

Factual Claims

It’s very hard, if not impossible to establish the absolute truth or falsity of most claims made in reasons and conclusions.

Instead of asking if a claim is true, we ask how dependable it is.

Fact vs. Opinion

The greater the quality and quantity of evidence supporting a claim, the more dependable it is. That is the difference between an opinion and a fact.

Bill Gates net worth was 61 billion as of March 2012.

His worth is a fact based on Microsoft’s share price and the number of shares he owns.

Aliens have visited the earth.

Much conflicting evidence about this.

When to AgreeThere are three instances in which you can agree

with a factual claim:

1. When the claim appears to be undisputed common knowledge, for example: Anti-virus software is the best way to protect a PC against infection.

2. When the claim is the conclusion from a well-reasoned argument.

3. When the claim is adequately supported by solid evidence.

What is Solid Evidence?

In the next three chapters, you learn how to evaluate different kinds of evidence.

In this chapter: Intuition Authorities and testimonials Personal Experience

IntuitionCommon sense, gut feelings or hunches.

Usually starts with:

“common sense tells us,”

“I know in my heart it’s true”

“I sense that”

Be wary of claims backed up only by intuition unless there is extensive personal experience behind it.

After 10 years, Mr. Lane always knew when something was wrong with his boat even before the overheating alarms went off or a funny noise started.

We Belong Together?God brought us together, can't you see,We belong together, you and me.Friends think I'm crazy, cuz we've never met,Say, how can you love someone from the internet?They say for all the girls online it's just a game,But I know in my heart, with you it's not the same!....From MY INTERNET LOVE -- © KAREN MASSIGAELL http://www.shecards.net/internetlove.html a poem about love online with a married man.

Common SenseCommon sense should tell you that your sister-in-

law is the last person on the planet who would send you an e-mail with this as the text: "This is a special funny website. I expect you would like it." From: Al Fasoldt’s “Should computer users have to get an operator's license?” http://aroundcny.com/technofile/texts/bit050102.html

He’s proving how stupid we can be about opening e-mail viruses.

Appeals to AuthorityClaims can be defended by appealing to sources

that are supposed to know more than we do about a given topic.

The perfect date movie! Reese Witherspoon is absolutely delightful!” Paul Starke, OXYGEN

“Two thumbs up!” Ebert and Roper

“It was not great but kind of cute” Lorene (Ms. Lane’s 80 year old Mom)

Regarding the movie Sweet Home Alabama

Evaluating AuthoritySome authorities are more careful in giving

opinions. The Wall Street Journal vs. the National Enquirer.

Authorities may disagree or be flat out wrong.

Bill Gates underestimated the impact of the Internet in the early 90’s.

Executives at Oracle, Sun and Netscape did not. Microsoft had to catch up.

Questions to Ask1. How much expertise or training does the

authority have on the subject about which he is communicating? Age does not confer expertise.

2. Was the authority in a position to have especially good access to pertinent facts? A first-hand observer or primary source is best.

3. Is there good reason to believe that the authority is relatively free of distorting influences? Bias, prejudice or kickbacks.

Appeals to AuthorityA UPS is a battery powered backup device that keeps the

computer running in the event of a power failure. These were found on the MinuteMan UPS web site:

"Our art and livelihoods are at the mercy of the AC power...the E1100 Minuteman UPS is the answer."--- Zoro (Drummer for Lenny Kravitz, Bobby Brown, Frankie Valli & The Four Seasons and many more) ...

"MINUTEMAN UPS has repeatedly proven to EDS that its products can eliminate power concerns in challenging situations."--- Neil Youngblood, MCSE, System Administrator Advanced, EDS

Authority?

Neil Youngblood is a believable authority. He’s a System Administrator, Advanced for a very large computer services company, EDS.

He is also a Microsoft Certified Systems Engineer (MCSE)

Not sure about Zoro the musician. Does a drummer have much first-hand experience in installing and setting up UPSs?

Personal TestimonialsQuoting particular persons as saying that a

given idea or product is good or bad based on their personal experiences.

Norton Anti-Virus does a great job of protecting my home computer against the viruses that students send me in their emails and homework attachment files. I highly recommend it.

Jim Porter

Evaluating Testimonials #1 Selectivity – the testimonial has been selected to show

the issue in the best light, what about the others?

Norton Anti-virus had problems freezing my system every night at 11:59, their fix (an update to the software) completely consumed my hard disk (allocating over 13 GIGA-bytes to its temporary files.) Bottom line Symantec (the makers of Norton utilities and other junk) do not check and Q/A their product, and are producing trash-software. Purchasing their product is a waste of your time and money. PLEASE consider other options. Shahram Shams (a consumer complaint from the web)

Evaluating Testimonials #2 Bias or Personal Interest – does the

person providing the testimonial have something to gain from it?

Does the person have any expertise to assist his or her judgment?

Omitted Information – sufficient information about the basis for the judgment is not provided. How do the person’s value assumptions affect his or her testimony?

Personal Experience

Our own personal experiences are very vivid in our memories.

We often rely on them, or on personal experiences reported to us those in our close circle (friends or relatives) as evidence to support a belief.

Problems with Personal ExperienceNot representativeSubject to hasty generalization fallacy.Demonstrates an outcome is possible, not typical.

I mentioned using the iMesh software to share music files over the Internet. My husband said “No way, the kids at school said you get viruses from iMesh. Kazaa is better.”

On further research, one kid got a virus downloading a program, not music.

If you see roaches at a restaurant, do you go back there again?

If your sister hit a big jackpot at the Luxor, would you gamble there?

End of Lecture