PT59.S3.Q19 - if understanding a word always involves

Comments

• nye8870 Alum ⭐

  November 2015 1749 karma

  This is what @DumbHollywoodActor had to say 4 months ago:
  "Okay. This question hurt me in the brains.
  Here’s my attempt at explaining it:
  
  First let’s translate the two sentences: If understanding a word always involves knowing its dictionary definition(UW→KDD), then understanding a word requires understanding the words that occur in that definition. (UW→UWOID) . Together that’s (UW→KDD)→(UW→UWOID).
  
  For funsies, let’s take the contrapositive of that: (UW and /UWOID)→(UW and /KDD). I chose to use the (A and /B) notation rather than the (A some /B) because in this case, it just made more sense to me. In other words, “If a person understands a word and doesn’t understand the words that occur in that definition, then there are some who understand a word and that understanding doesn’t always involve knowing its dictionary definition.”
  
  Sentence 2:But clearly there are people — for example, all babies– who do not know the dictionary definitions of some of the words they utter. (B→/UWOID)
  
  Analysis: We’re so close to triggering something in this logical chain. With “Babies don’t know the dictionary definitions of words they utter”, we’re so close to denying the necessary condition of that embedded clause. The only problem is that we’re not sure if babies can understand the words that they utter. Everything about this problem hinges on that fact. If they can understand the words that they utter, then we can trigger the negation of the sufficient condition, that understanding a word DOES NOT always involve knowing its dictionary definition.
  
  Elimination: (A) This is more of a could be true, not a must be true. We just don’t have enough information and logically, we can’t make that inference unless we know that babies can understand the words that they utter. (B) This is VERY close. The problem is we need this to be a given, not a final inference. If this is a given, we can make some inferences, but we can’t infer this statement based on the information that we’ve been given. (C) Okay. Now, we have some conditional statements, which is good because it will help us to make an inference. Unfortunately, this sufficient condition won’t trigger anything. It’s practically reiterating the last sentence of the stimulus. (D) has the same problem. (E) looks good.
  
  Selection: Wow, this is a long explanation. Wake up! We’re getting towards the end! (E) works because it gives us a sufficient condition that we can work with because if we combine the sufficient condition (some babies understand all the words they utter) with the condition in the last sentence of the stimulus (all babies don’t know the dictionary definitions of some of the words that they utter), we can trigger a denial of the necessary condition of the first sentence (understanding a word requires understanding the words that occur in that definition), and then negate the sufficient condition of the first sentence of the stimulus (If understanding a word always involves knowing its dictionary definition) which matches up beautifully witht the necessary condition of answer (E) (understanding a word does not always involve knowing its dictionary definition.)
  
  If you’ve made it this far, I thank you. And I hope this might have helped."
• DumbHollywoodActor Alum Inactive ⭐

  November 2015 7468 karma

  @nye8870 Ha! I wonder how helpful that explanation really was.