Logical Reasoning

PT140 · S2 · Q3 Humorous television advertisements

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Humorous television advertisements are the only effective ones.

Conclusion

Humorous television advertisements are the only effective ones.

Evidence (for)

If something is humorous it will not only attract people's attention, it will hold their attention long enough for a message to be conveyed.

For an advertisement to be effective, it must convey its message.

Evaluate

Whenever we're doing Flaw and we see conditional logic ("the only", "if", "must"), we should be immediately suspicious that they're testing the #1 famous flaw, Necessary vs. Sufficient, in which an author presents a conditional rule but applies it illegally in a backwards or negated fashion.

The conclusion looks like this: Effective -----------------------> Humorous ~Humorous ---------------------> ~Effective

What do the two conditionals in the evidence look like? Humorous ---> holds attention long enough to convey message

Effective → conveys message

When two conditionals are being used, only one is being broken, so we have to figure out which one that is.

We can tell here that the 1st one must be the one that's broken, since the Conclusion involves "Effective" on the left of the arrow, but it does not involve "Humorous" on the left of the arrow.

The author is apparently thinking that the two premises fit together like this:

Effective → conveys → Humorous message

That's how she's deriving her conclusion, Effective ---------------> Humorous

But the 1st conditional premise doesn't say, conveys message → Humorous it says Humorous → conveys message

Goal

Look for an answer calling out a Necessary vs. Sufficient flaw with the conditional connecting "Humorous" and "holds attention long enough to convey message". Humor is sufficient to do that, but the author is acting like it's necessary.

Or look for a conversational answer saying,

3.

Which one of the following most accurately describes a flaw in the argument?

  1. Correct

    It takes for granted that

    Why this is right

    This describes the illegal backwards version of the 2nd sentence that the author was imagining to make her logic work: ~Humor → ~Grab attention to convey message Grabs attention to convey message → Humor We can tell the author was assuming this, because if you negate it and say, "Hey, author -- stuff besides humor can attract a person's attention and hold it long enough for a message to be conveyed", it would weaken the argument and make it seem like humorous ads are not the only effective ones.

    Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.

    69% picked this

  2. It confuses attracting a person's

    Doesn't Confuse

    While the 3rd sentence only talks about "conveying message" whereas the 2nd one talks about "attracting attention and holding it long enough to convey the message", the author isn't confusing them or making an illegal move there. The author thinks that effectiveness requires conveying a message. And conveying a message implicitly requires attracting a listener's attention and holding it long enough for the message to be conveyed. The author doesn't spell that out, but we wouldn't criticize her for that. We all understand that conveying a message requires getting someone's attention and holding it long enough for the message to be conveyed.

    6% picked this

  3. It treats a necessary condition

    Wrong Conditional

    The author committed a Necessary vs. Sufficient flaw with the 1st conditional (the one about humor / holding attention long enough). The author didn't do anything wrong with the second conditional, which was about what's required for an ad to be effective. The author establishes that a necessary condition of an ad being effective is that it conveys its message. The author never treated "conveying a message" as sufficient to make an argument effective. That would have sounded like, "For an ad to be effective it must convey its message. The new ad for Pop Tarts conveyed its message. Thus, the new ad for Pop Tarts was effective." This answer reflects the modern "Bait and Switch" trap answers that occur with famous flaws. They've been testing these same 10 flaws so much for nearly 100 LSATs, that they have to try to complicate how we process them. A trick they like using is presenting two conditional premises, so that they can write a trap answer that targets the conditional that was used correctly. We want to make sure we get specific with our thinking upfront about which of the two conditionals is actually being read backwards / opposite.

    20% picked this

  4. It uses two senses of

    Not Equivocation

    This describes the famous Equivocation flaw, in which an author cites the same term/concept twice, as though it's being used consistently, even though it's really being used in two very different ways. We could equivocate with "effective" if one usage meant "it fulfilled its purpose" and another usage meant "it took effect on this date". But the two uses of effective in this argument are the same.

    1% picked this

  5. It takes for granted that

    Too Strong: only purpose

    Nothing in here talks about the purpose of an advertisement, let alone makes it seem like an advertisement only has one purpose.

    4% picked this

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