#13 - Columnist: Computer voice-recognition technology

[Brook Miscoski]

Lily,

Distinguishing between (A) and (D) requires focus on what the stimulus is trying to prove.

The stimulus is trying to prove:

AT RR

To elaborate, the stimulus already includes the following concept:

AT DH.

The stimulus hasn't explicitly stated that, but a translation that doesn't distinguish between similar sounding words won't be an accurate transcription. What the stimulus hasn't done is to establish why RR is necessary for DH--in the conclusion:

AT DH RR, the second relationship isn't established.

Looking at the choices (D) and (A);

(D) makes the argument:

RR DH

Because RR is a sufficient condition in (D), it will not help establish RR as a necessary condition.

(A) makes the argument:

DH RR

Which makes (A) superior since (A) is helping to establish that RR will be a requirement.

---to elaborate further--

Where this can all go horribly wrong--and I followed you there to see it--is if you go about linking diagrammed conditional reasoning together without asking yourself whether the step is justified.

The contrapositive of (D) is:

-DH -RR

The contrapositive of the conclusion of the stimulus is:

-RR -AT

And the first sentence of the stimulus provides:

C -DH.

You can link that all into:

C -DH -RR -AT,
AT RR DH -C

This seems very satisfying, but you haven't established the conclusion that AT RR, you've just linked it into a chain. Stay mindful of why you are diagramming, and you will avoid this trap.

[Lily123]

Thank you for the explanation. I just want to clarify my question/understanding a bit.

I understand the stimulus is trying to prove AT RR
I also understand the stimulus implicitly includes AT DH

What the stimulus hasn't done is to establish why RR is necessary for DH

This is what I don't understand:

How do we know RR is necessary for DH & not the other way around?

(D) makes the argument:

RR DH

Because RR is a sufficient condition in (D), it will not help establish RR as a necessary condition.

This is my point & the reason I picked D:

I thought that in order to establish RR as the necessary condition for AT, it must be linked directly to AT in the chain (as opposed to just an indirect relationship).

Are you saying that in order to establish RR as the necessary condition for AT, it must be at the end of the chain (i.e., it must be necessary for ALL the other elements as well)?

AT RR DH -C

This seems very satisfying, but you haven't established the conclusion that AT RR, you've just linked it into a chain.

When I look at this chain, RR is clearly necessary for AT.
I think what you're saying is: the connection between RR to AT is arbitrary -- just because RR & DH are connected, it doesn't mean it has anything to do with AT.
The only thing that's proven by (D) is:      RR DH AT

More generally, if we have
[P] A C D
[C] A B

It's not enough to just establish B C because the connection to A would be arbitrary
What we would need to prove the conclusion is: D B so we get A C D B
Is this correct?

In this example, would C B also prove the conclusion by giving us: A C B?

Essentially, does RR need to be necessary for ALL the other elements to connect the premises & prove the conclusion? If so, is this always true of a necessary condition in the conclusion (i.e., if we have a conditional conclusion, the necessary condition of the conclusion must be necessary for ALL relevant evidence in order for it to be necessary in the conclusion)?

[James Finch]

Hi Lily,

This is a classic Supporter Assumption, which operate very similarly to Justify questions in that they introduce a new term in the conclusion that must be linked to the premises. These tend to be conditional, because that's the easiest way to make these connections.

Here we have:

Premise: AT DH

Conclusion: AT RR

Conclusions are inferences, so the Prephrase should be that this is a A C inference, requiring that we add the following assumption:

Assumption: DH RR

Which allows for a properly drawn chain of: AT DH RR, or to simplify, AT RR. Fits like a glove, and is exactly what (A) gives us, making it the correct answer choice.

If we contrast that to (D), we can see that it doesn't actually help us get to the A C inference:

Premise: AT DH

Conclusion: AT RR

Assumption (D): RR DH

Assumptions act as unstated premises, and when taken with the premises given should add up to the conclusion. Here, if we put (D) together with the premise, we get:

AT or RR DH

That's not the conclusion, and doesn't help us get there; AT RR is left unproven, as we don't have any relationship that we can infer between the two conditions. They both could act as sufficient conditions for DH, but that isn't where we need to go logically. Only (A) actually proves the chain.

Hope this clears things up!

[ataraxia10]

In hindsight, I realize I would have recognized A as the answer if I had used the Assumption Negation Technique. Are there Assumption questions that are more appropriate for applying ANT and can save time/confusion?

[Jeremy Press]

Hi ataraxia10,

My recommendation with the Assumption Negation Technique is to wait until you've eliminated some clear loser answer choices before applying it. Most assumption questions have at least two to three answers that are not necessary for clear reasons: for example, because they're far too exaggerated, or because they're discussing subjects that are well outside the scope of the argument. Once you've got your contenders, get aggressive about trying out the technique. In my experience there isn't one definitive kind of stimulus that will signal you to try the technique. And the great thing about the Assumption Negation Technique is that it can be used on ANY assumption question to reveal the correct answer.

That being said I personally (and this is a very personal thing) find the technique more revelatory on Defender Assumption questions (where the answer "assumes away" a potential attack on the argument). This is a Supporter Assumption question (where the answer supplies a missing link in the argument), but as you've noted, the technique works here for you. So long story short, wait until you've got your contender answers, then aggressively apply the Assumption Negation Technique to those contenders.

I hope this helps!

Jeremy

[Stacks1990]

Hello,

I am just curious, is (B) a mistaken reversal of the conditional statement present in the conclusion?

When it comes to assumption questions involving conditionality, especially when its going into the latter stages of the section, I find myself having difficulty. Any tips regarding the last 10 questions would be greatly appreciated.

[Jeremy Press]

Hi Stacks,

Yes, you've nailed the problem with answer choice B precisely--it is a Mistaken Reversal of the conditional statement in the conclusion. Nicely done!

Any time you're dealing with conditional statements like these (the conclusion of this stimulus, answer choice B of this question, etc.), your best bet is to bite the bullet and diagram. That's because, first, the conclusion of the stimulus uses "until," which creates a tricky conditional relationship that students commonly misinterpret when not forced to diagram; and, second, both the conclusion and answer choice B have very "wordy" conditions (in both the sufficient and necessary parts of the relationship) and the LSAT writers know you're likely to misinterpret things the more language they pack into them.

So, when you're diagramming (and you should be, especially in the last ten to twelve questions of the section), strive to produce the simplest possible diagram that still accurately reflects the notions of the statements. That way you have the relationships down cold and you won't miss things like the Mistaken Reversal answer in answer choice B.

I hope this helps!

Jeremy

[VamosRafa19]

Hi, I'm a little confused by the question type. This says assumption required, which I read as necessary assumption. But it seems that A is actually justifying the conclusion. If we have A then the conclusion has to be true. I thought we were looking for is given the conclusion is true, what follows? Basically I thought it was SA Conclusion True NA. I thought this question was looking for NA, but answer seems to be SA. What am I missing? Is it both?

[Adam Tyson]

If an assumption is required, amosRafa19, then it is necessary, so this is absolutely a Necessary Assumption question. Sometimes, though, a necessary assumption is also sufficient to prove the conclusion, and they could just as easily have asked us the other question type and wound up with the same answer. The same thing happens with some Strengthen questions, where the answer is strong enough to Justify the Conclusion (Sufficient Assumption) and also might be something the author had to assume (Necessary Assumption). Here's a simple example:

All dogs are cute, so Monroe is cute.

What would strengthen this argument? Monroe is a dog.

What is a necessary assumption of this argument? Monroe is a dog.

What would justify the conclusion of this argument? Monroe is a dog.

One answer does all three! So don't worry that answer A in this question looks like it justifies the conclusion (which I do believe it does). It is still a necessary assumption, without which the argument would make no sense, and is therefore correct.

[quan-tang@hotmail.com]

Accurate Translation Distinguishing Homophone

My problem with the question is even after reading and reading again, I cannot find where in the premise that is stated that translate -> distinguishing homophone. The phrase ' As a consequence, ' was placed in a way its exact inference is extremely vague.

Hi Sodomojo,

The premise given in this stimulus is that voice-recognition technology cannot distinguish between homophones. Then we are given the conclusion as a conditional statement, that until voice-recognition tech can recognize and utilize grammatical and semantic relations among words, these programs won't accurately translate spoken words into text (Accurate translation Grammar & Semantics). The phrase "as a consequence" serves to link the original premise as a conditional statement to the sufficient condition of accurate translation of speech-to-text.

As an assumption question, there is a clear logical break between distinguishing homophones, which has been tied to accurate translations, and recognizing grammar and semantics. The phrase "as a consequence" serves to link the original premise as a conditional statement to the sufficient condition of accurate translation, so the conditional relationship we actually have is:

Accurate Translation Distinguishing Homophone Grammar & Semantics

with the logical break occurring between the homophones and the grammar and semantics conditions. We have an A B C conditional relationship, but B C doesn't exist, yet the conclusion still draws the inference that A C.

Answer choices (A) and (D) both link homophones and grammar and semantics, but in opposite ways. (A) makes grammar and semantics the necessary condition for the sufficient condition of distinguishing homophones, bridging the gap in the stimulus by linking B C, allowing us to then draw the conclusion's inference of A C.

(D) on the hand makes distinguishing homophones the necessary condition for recognizing grammar and semantics, essentially reading the stimulus as:

Accurate translation Recognize Grammar & Semantics Homophones

while tacking on an unnecessary B C conditional relationship. However, this isn't the reasoning in the stimulus, and not the assumption that is required for the logic to hold true, but a Mistaken Reversal of it. So (D) is an incorrect answer choice.

Hope this clears things up!