#19 - If understanding a word always involves knowing

[David Boyle]

Hi David,

I'm still a little confused. I can understand why (E) is correct but I don't understand why (A) also couldn't be correct because it seems as if (A) could be an inference based off of the stimulus? The only reason I could think of for why (A) is incorrect is because the statement is too strong for the conditional nature of the stimulus and it does not contain conditionality correct? Should I be looking for an answer choice that contains a conditional statement anytime there is a must be true stimulus with conditionality?

Also, could you please diagram the entire conditional stimulus for me thoroughly without abbreviations. I really appreciate it!

Thanks!

Hello SMR,

Diagramming:

understanding a word knowing dictionary definition understanding words in that definition

people slash knowing dictionary definitions of some of the words they utter

babies slash knowing dictionary definitions of some of the words they utter

So, as I said previously, answer A is tempting, but since

knowing dictionary definition understanding words in that definition

, "understanding words" is the necessary, not the sufficient. The necessary is often a larger set than the sufficient. (E.g., "Every fish is an animal", and "animal" is a larger set than "fish".) So one could understand words in a dictionary definition (the necessary), without knowing the dictionary definition (the sufficient), sort of as if you have a dream, and you understand the words in the dream, but you don't understand the whole dream. To understand the whole dream, you would have to understand all the words in it; but you could misunderstand the whole dream, while still understanding the words in it. The larger set "understand the words in the dream" includes the subsets "understands the whole dream" and "doesn't understand the whole dream". Whew!

So, a baby, even if he/she doesn't know a dictionary definition, could somehow understand the words in the definition. (That may sound stupid, but I'm just following the diagramming. Maybe the "understanding" is on some emotional, non-logical level, maybe?)

So, we don't know babies utter individual words they don't understand. But answer E makes sense, because even if some babies understand, we know from the stimulus that none of them knows every single dictionary definition of every word he/she utters.

And no, as for "Should I be looking for an answer choice that contains a conditional statement anytime there is a must be true stimulus with conditionality?", not necessarily. If the stimulus says, "If I am happy, I eat ice cream. I am happy.", then "I eat ice cream" could be the correct answer, even though it is not a conditional statement.

Hope this helps,
David

[karen_k]

Hi,

I picked A as my answer choice. After reviewing, I understand why E is correct but am not exactly sure why A is incorrect..? Thanks in advance!

[Emily Haney-Caron]

Hi Karen!

The reason A is incorrect is because we don't know for sure that understanding a word always involves knowing its dictionary definition; we just know what happens IF that is true.

Does that help?

[mpoulson]

Hello,

I have read the explanations provided, but I am still not getting why A is wrong and E is right. How is it possible that babies don't understand the Dictionary Definition of a word but they are still able to understand all individual words? Doesn't that directly conflict with the contrapositive if you do not understand the dictionary definition of a word then you don't understand that word (since understanding always involves knowing the dictionary definition of a word). I don't get why E is right either. The text says that all babes do not know the DD of some words, so how is possible that there are some other babies that understand all words they utter (knowing the DD is necessary for understanding a word). Can you explain this in a simple, but detailed way?

- Micah

[Emily Haney-Caron]

Hi Micah,

I think the problem you're having here is that you're taking the first sentence as absolutely true. But we don't know that it is true - we only know what happens IF it is true. This is a formal logic problem, rather than conditional reasoning. Try to think of the first sentence as an argument that is being made, and the second sentence as a piece of evidence that seems to contradict that argument.

Does that help?

[mpoulson]

So what would alert the reader that we have entered an arena of formal logic and not conditional reasoning for this question? So does diagramming not apply? The responses below mostly employ the use of diagramming which I thought was Conditional Reasoning. I am in the Live Online Class. Can you direct me to any course materials that provide a review of formal logic or similar logic questions?

[Nikki Siclunov]

Hi Micah,

The reason why with talk about Formal Logic here, as opposed to garden-variety conditional reasoning, is because of the qualifier "some people" which usually requires special handling. For instance, if "some monkeys are smart," we usually diagram this as monkeys smart. Formal Logic is no longer a significant part of the test, and in fact this question can be understood without knowing its mechanics. If you're curious about it, it's something we discuss in a supplemental Virtual module under Lesson 8, available on the Online Student Center.

The reasoning in this problem contains a rare form of "nested" conditional statements, where a conditional relationship is itself a condition (sufficient or necessary) in another conditional relationship.

Now, let's take a look at the stimulus at hand.

UW = Understand Word
KDD = Know the dictionary definition
UWDD = Understand all words in the dictionary definition

• (UW KDD) (UW UWDD)

The question is this: what if some people (such as babies) don't know the dictionary definitions of some of the words they utter? In other words, what if KDD(babies)? The important thing to recognize is that this fact alone doesn't necessarily mean that babies don't understand the words that they utter, because the relationship between understanding a word and knowing the D.Def of that word is not necessarily a given: it is merely a hypothetical (if....), functioning as a sufficient condition for the necessary condition in the above diagram. My prephrase would instead be this:

Either some babies don't understand all the words that they utter, OR ELSE THEY DO understand them, in which case the conditional relationship between understanding a word and knowing its dictionary definition is just bogus.

This agrees with answer choice (E): if some babies understand all the words that they utter without knowing the dictionary definition of these words (as the stimulus indicates), then clearly understanding a word doesn't involve always knowing its definition. To disprove a conditional relationship, all you need to do is show that the sufficient condition can occur in the absence of the necessary condition. That's precisely what (E) suggests, concluding that the conditional relationship is not true.

Let me know if this helps!

Thanks.

[mpoulson]

Thank you. I follow your logic and it makes sense. What I don't understand is why is A wrong? I don't see anything that makes it particularly invalid. From my perspective, the only thing that would make it incorrect is if I don't accept the first premise as true and because the second statement is more definitive saying "clearly there are people (babies) who do not know the DD of some of the words they utter" then that would I guess lead to less support for A than E. Please explain.

[Nikki Siclunov]

Micah,

Answer choice (A) is incorrect, as previously explained, because it doesn't contradict a premise. It contradicts a hypothetical - there is a big difference between the two! The conditional relationship between understanding a word and knowing its dictionary definition is not an absolute given. Read my explanation above It's merely a hypothetical that would be true only if a certain necessary condition is met.

In other words, it's entirely possible that babies understand all of the words that they utter, even if they don't know their dictionary definitions. Why? Because that's the implication of the contrapositive of the first sentence: if understanding a word doesn't always involve understanding all the words that occur in the dictionary definition of that word, then a baby (or anyone) can understand a word without knowing its dictionary definition. This is simply the contrapositive of the first sentence.

Thanks!

[lathlee]

This is nested Q

UW = Understand Word
KDD = Know the dictionary definition
UWDD = Understand all words in the dictionary definition
UW KDD UWDD

Then contrastive would be
Negation UWDD Negation KDD Negation UW
AKA:
Negation UWDD
+ Negation UW
Negation KDD

Applying powerscore nested rule:
UW UWDD OR KDD

So the answer would be E) CUZ
if UW occurs, one or both of OR Condition(s) has or both to occur in necessary condition

Since Some of All babies babies UW UWDD OR Negation KDD is fine
E) is fine