At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
That swan is white. Therefore, all swans are white. What do you think is wrong with that statement?
not all swans are white?
Potentially. But in terms of the actual statement, can you determine what's wrong? Is it a fair conclusion for me to form?
Okay, why not?
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?
i don't understand
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?
because you only gooten two ripped bills?
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?"
it will only take one person to get an A to disprove there theory?
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?
Okay, why not?
because it was only 3 people who she knows got an B
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).
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.