Credibility and Bias Reasoning Skills Help (page 3)

Introduction to Credibility and Bias Reasoning Skills

"Begin challenging your own assumptions. Your assumptions are your windows on the world. Scrub them off every once in awhile, or the light won't come in."

—Alan Alda, American actor (1936–)

Lesson Summary

When we're faced with opinions and tentative truths, it's important to know how much we can trust our sources and how much they know about the subject at hand. This lesson will teach you how to evaluate the credibility of your sources so that you can make well-informed decisions.

You've decided you'd like to see a movie tonight, but you're not sure what to see. You're thinking about catching the latest Steven Spielberg movie, so you decide to find out what others think of it. Your coworker, who goes to the movies at least twice a week, says it's one of the best films he's ever seen, that you'll love it. Your sister, a legal secretary who knows you very well, says she thought it was OK, but she thinks you'll hate it. A review in the Times calls it "dull" and "uninspired," a "real disappointment." The full-page ad in the Times, however, calls it "dazzling," a "true cinematic triumph," and gives it "two thumbs up." So, do you go to see the movie or not?

In this instance, you're faced with many opinions—what various people think about the movie. So whose opinion should you value the most here? How do you make your decision?

What Is Credibility?

When you're faced with a variety of opinions, one of the most important things to consider is the credibility of those giving their opinion. That is, you need to consider whose opinion is the most trustworthy and valid in the particular situation.

Credibility: believability; trustworthiness

Credibility also plays a very important role when dealing with those tentative truths you encountered in the last lesson. Whenever you're offered opinions or facts that you aren't comfortable accepting and aren't able to verify, the credibility of your source is crucial in helping you decide whether or not to accept these opinions or tentative truths.

How to Determine Credibility

Several factors determine the credibility of a source. One is your previous experience with that source. Do you have any reason to doubt the truthfulness or reliability of this source based on past experience?

Next, you need to consider your source's potential for bias as well as level of expertise. But let's return to our opening scenario for a moment. In this situation, we have four different opinions to consider:

• What your coworker thinks
• What your sister thinks
• What the Times review says
• What the Times ad says

Of the four, which is probably the least credible (least trustworthy) source, and why?

Tip

One way to better understand the difference between fact and opinion is to read the news in your local newspaper and then again in the tabloids. Watch what words are used in each one. See how many facts you can spot in each story. How do they differ?

You should have chosen the Times advertisement as the least credible source. Why? Simply because it is an ad, and no advertisement is going to say anything bad about the product it's trying to sell, is it? Advertisements generally have limited credibility because they're biased.

Recognizing Bias

A bias is an opinion or feeling that strongly favors one side over others; a predisposition to support one side; or a prejudice against other sides. The full-page ad in the Times clearly has a vested interest in supporting the movie. No matter how good or how bad it really is, the ad is going to print only favorable comments so that you will go see the film.

Advertising has a clear money-making agenda. But bias is prevalent in everyday situations, too. For example, you may be less likely to believe what your neighbor has to say about candidate Warren, simply because your neighbor keeps thoughtlessly starting construction on the new addition to his house at 6 a.m. In that case, you'd be influenced by your annoyance with your neighbor rather than the validity of his opinion. You need to remember to separate your feelings about your neighbor from what he actually has to say.

Similarly, another neighbor may have great things to say about candidate Warren, but if you know that this neighbor is Warren's cousin, or that Warren has promised your neighbor a seat on the local council, then you can see that your neighbor has something at stake in getting you to vote for Warren. It's important, therefore, to know as much as possible about your sources when deciding how heavily to weigh their opinions.

Tip

When you read any information that is being presented as facts, check out who sponsored that information. Who was responsible for compiling and presenting the data? Does this person, group or organization have a personal interest or investment in the topic? If so, start looking at these so called facts for possible biases.

Level of Expertise

Return now to the opening example about the movie. You're down to three possible choices. How do you determine whose opinion is most credible? It's not going to be easy, but let's provide some additional criteria for determining credibility. Once you identify any possible biases, you need to carefully consider the next criteria: expertise.

Generally speaking, the more a person knows about a subject—the more expertise he or she has in that area—the more comfortable you should feel accepting his or her opinion. That is, in general, the greater the expertise, the greater the credibility.

In this situation, expertise falls into two categories: knowledge of movies and knowledge of you and your personal tastes. So you need to consider how much these three sources know about what makes a good movie and how much these three sources know about what you enjoy in a film.

Determining Level of Expertise

In many a courtroom, lawyers will call an "expert witness" to the stand to support their case. For example, in a murder case where the defendant is pleading insanity, the prosecution and the defense might call upon psychologists who can provide expert opinions about the defendant's ability to distinguish between right and wrong. These expert witnesses are usually outside the case—that is, they are not involved in the alleged crime and do not have any relationship to or with the defendant; otherwise, they might be biased.

For this testimony to be helpful to either side, however, the jury must be convinced that the expert witness is indeed an expert; they must be assured of his or her credibility. The lawyers will help establish the witness's credibility by pointing out one or more of the following credentials:

• Education
• Experience
• Job or position
• Reputation
• Achievements

These five criteria are what you should examine when determining someone's level of expertise and therefore credibility. One category is not necessarily more important than the other, though generally a person's education and experience carry the most weight.

An outstanding expert witness at this trial, therefore, might have the following profile:

Dr. Joanne Francis

Education: PhD, Harvard University

Experience: Ten years at County Medical Hospital; 15 years at Harvard Psychiatric Center

Position: Chief of Psychiatric Care at Harvard Psychiatric Center; teaches graduate courses at Harvard

Reputation: Ranked one of the ten best on the East Coast

Accomplishments: Has won several awards; was asked to serve on a federal judicial committee to establish guidelines for determining insanity; has written three textbooks and published 20 journal articles

Notice how strong Dr. Francis is in each of the five categories.