#15 - Proofs relying crucially on computers provide less

[Administrator]

Complete Question Explanation

Must Be True. The correct answer choice is (B)

The discussion here involves proofs and the need for computers. Proofs that are completely reliant
on computers provide us with less certainty, because we cannot “check their work,” so to speak, or
verify their findings on our own, independently, without the use of computers.

This is distinguishable from proofs that do not rely on computers—basic operations in math, for
example, can be calculated by computer and verified by human calculation. The author points out
that calculators are often used for convenience, but such cases are different, because the calculator is
used for convenience (and not out of necessity).

A Must question stem follows, so we should look for the choice that can be confirmed with the
information provided by the author.

Answer choice (A): The language used in this choice is far stronger than justified by the stimulus.
The bold claim in this choice is that any help from computers will make it impossible to judge a
proof with any degree of certainty. The stimulus provides only that the level of certainty is decreased
where results cannot be independently verified.

Answer choice (B): This is the correct answer choice. The problem with computer reliant proofs,
according to the author, is that humans cannot verify their accuracy—thus the need for computers.
Such proofs provide less certainty because humans cannot verify their accuracy (some mistakes
might be undetectable).

Answer choice (C): This choice is disproved with the author’s discussion of the use of calculators.
The author provides that a calculator is often used even though humans can verify the results; in such
cases the degree of certainty is not reduced, because the computer is not an absolute necessity, but
rather a convenience, and the results can still be verified independently.

Answer choice (D): Like incorrect answer choice (A), the strong language used in this choice takes
it out of contention. The author’s point is that when independent human verification is possible, we
can be more certain than when such independent verification is impossible. This is not the same,
however, as claiming that human verification equates to complete certainly. Because of the strength
of the language used in this choice, it is incorrect.

Answer choice (E): The creation of proofs that rely crucially on computers is an example of
computers supplementing the cognitive abilities of humans. Since this supplementing of our
cognitive abilities is clearly possible according to the author, this cannot be the correct answer
choice.

[smile22]

I can see how answer B is supported by the stimulus. However, C seems equally attractive. Why is C incorrect?

[David Boyle]

I can see how answer B is supported by the stimulus. However, C seems equally attractive. Why is C incorrect?

Hello,

The wording of B vis-a-vis C is a little tricky, true.
Answer B basically says, "Proofs really needing computers may have errors humans can't find." Answer C basically says, "ANY time a computer's used, proof is less certain." So answer B is more moderate, less extreme, which is in itself a point in its favor.
Also, answer B tracks the passage more, since the passage talks about crucial use of computers in proofs, not just sporadic, tiny use. Answer C says that *any* use of computers messes up proofs, and doesn't say whether the computer's used crucially in a proof or not.

David

[smile22]

Thank you for the explanation!

[PresidentLSAT]

What is the difference between “Must Be True” and “Most Strongly Supported.”

I’m confused about the explanation for C. It’s supported by the stimulus that when a computer is involved, certainty is reduced (first sentence in stimulus). C says, the introduction of a computer alone is enough to justify that our level of certainty reduces.

Per the explanation, this answer is disproved but the stimulus almost explicitly states it. Is the author here undermining her own statements in the premise?

I can see it from a different angle but multiple perspectives come into play when approaching such a question. The examples at the end of the stimulus basically illustrate an exception that a computer replacing a human did not decrease certainty in this case. It’s still iffy

[Adam Tyson]

The difference between Must Be True and Most Strongly Supported is just one of degree, PresidentLSAT. We typically treat them as being the same type of question, Must Be True, because they are both based solely on the facts in the stimulus, which are used to support an answer choice. But the answer to a Most Strongly Supported question an be less than 100% certain. It's the only answer that is a reasonable inference to make under the facts given, and usually has a lot of support, but there can be some room for error. In a Must Be True, there isn't supposed to be any such wiggle room, and the correct answer is proven by the stimulus. Other answer may be supported and may seem likely, but they are not necessary.

The problem with answer C is the use of "whenever," which is too strong under these facts and which is disproven by the fact that a proof done by a human using an electronic calculator can be just as certain as one done based on human cognition alone. The stimulus only proves that proofs that rely crucially on computers are less certain than those that do not. That's not all computer assisted proofs, but only some of them. Thus, answer C overstates the facts, while answer B follows them.