Question

Consider the following situation and explain what might be a problem with the credibility of the source or the thinking involved: You got your essay back in English class and you received a "B" on it. The girl sitting behind you, a friend of yours, also received a "B" and her boyfriend, who is another period class with the same teacher and the same subject, also received a "B." You concluded then that no one that wrote that particular assignment for that particular teacher received an "A." Pitfalls in credibility?
help please

Answer 1

That swan is white. Therefore, all swans are white.

What do you think is wrong with that statement?

Answer 2

not all swans are white?

Answer 3

Potentially. But in terms of the actual statement, can you determine what's wrong? Is it a fair conclusion for me to form?

Answer 4

No?

Answer 5

Okay, why not?

Answer 6

If I've only ever seen one swan, and it was white, it is scientifically "true" that all swans are white. But what is the caveat?

Answer 7

i don't understand

Answer 8

If I get a $5 bill and it is ripped, I might say all money is ripped. Let's say the next bill I get is also ripped. That continues to support my theory. But what is the problem? Is it fair for me to extrapolate that to all bills? (Hint: No.) Why not?

Answer 9

because you only gooten two ripped bills?

Answer 10

Right. All it will take is one bill that isn't ripped to disprove my theory.

Just as it only takes one black swan to disprove my theory that all swans are white.

That is what science is all about. Theories exist until they no longer work. Many theories, like the law of gravity, have been observed so much that they are taken to be self-evident. (But keep in mind that it would only take one instance of no gravity (and I don't mean like in space—there is still gravity) to disprove the theory.

So, back to your original question. What is the problem with the "experiment?"

Answer 11

it will only take one person to get an A to disprove there theory?

Answer 12

Exactly! How many people did "you" ask, and how many people do you think are in the two classes (don't need an actual number—just think about it relatively).

Is it fair to base your assumption on such a sample size?

Answer 13

no

Answer 14

Okay, why not?

Answer 15

because it was only 3 people who she knows got an B

Answer 16

Exactly! There are dozens of potential classmates she didn't ask, so it's not a fair conclusion to make when she only asked 3 (one being herself).

Answer 17

Thanks!!!

Answer 18

No problem. So, it's not so much an issue of credibility (you can assume your friend and her boyfriend told you the truth), but certainly a problem with the thinking involved. This is an inference based on too little evidence. (Though, if you don't understand what an inference is, I wouldn't use it in your answer. ;)

Good for you for working through the problem. Nice to see.