#17 - Zelda: Dr. Ladlow, a research psychologist, has

[Dave Killoran]

Complete Question Explanation

Must-SN. The correct answer choice is (B)

As always, the first step in solving a problem is to know what each party said:

• Zelda begins by talking about Dr. Ladlow, saying he has proven that his theory makes accurate predictions about rats, and that on that basis, Ladlow claims his theory is "irrefutably" correct. Note how powerful that claim is: he's saying there's no way his theory is wrong.
  
  Anson replies by laying out an argument in the following order: conclusion, premise, premise. And, it's an argument that uses a contrapositive to arrive at that conclusion. Let's take a look at that argument in reverse order, for clarity:
  
  
  • Anson ends by invoking a conditional relationship: "Responsible psychologists always accept the possibility that new evidence will show that their theories are incorrect." Or, in diagram form:
    
    RP = Responsible psychologists
    ANE = accept the possibility that new evidence will show that their theories are incorrect.
    
    
    RP ANE
    
    
    However, Ladlow has already claimed the theory is irrefutably correct (and in other words, cannot be disproved), and thus Ladlow is saying that he will not accept new evidence, or conditionally speaking:
    
    
    ANE
    
    
    This information triggers a contrapositive, resulting in Anson concluding that Ladlow is not a responsible psychologist:
    
    
    RP

The question stem here is a Must Be True question, and notably it focuses on Anson's statements. Thus, you must find the statement in the answers that is true based on what Anson said (and not Zelda).



Answer choice (A): The problem with this answer is the word "inaccurate." Anson does not say the evidence is inaccurate, just that it may be inadequate or not fully conclusive.

Answer choice (B): This is the correct answer. This answer is just a restatement of Anson's conditional premise. The test makers do take some pains to avoid easy identification though. For example, the "Psychologists" at the start are separated from the "responsibly" that appears near the end, but when combined those terms refer to "responsible psychologists," which is the same group Anson referred to. And the phrase "cannot be disproved" is the same as irrefutable or always correct. And why is is that these responsible psychologists cannot conclude they cannot be disproved? Because they accept new evidence, mirroring the RP ANE premise Anson used.

Answer choice (C): Nothing in what Anson says suggests that psychologists "can never develop correct theoretical explanations."

Answer choice (D): It's not that responsible psychologists don't make predictions, it is instead that the do not claim they are irrefutably correct.

Answer choice (E): This very attractive wrong answer is a Mistaken Reversal of the principle that Anson cites. Whereas Anson stated that:

• RP ANE
  
  
  This answers states:
  
  
  ANE RP

[maximbasu]

Hi,
I understand that B is correct but I do not understand how E is wrong. E states exactly what the stimulus talks about.

Rgs,
Maxim

[Dave Killoran]

Hi Maxim,

Thanks for the question! You've asked about one of my very favorite questions. However, I'm not going to initially just explain this one. Looking over the questions you are posting, I'm getting the feeling you are flying through doing problems without really analyzing what's going on in each one. In my experience, that's an easy trap to fall into but it also doesn't help you very much when you are trying to improve. This is a problem that isn't related so much to doing a lot of problems, but rather to how you review the problems that you do complete. So, I'm first going to give you some thoughts on how to review these problems, and then I'll come back to this particular problem

Below is the method I generally recommend for reviewing practice tests or problem sets:

Delayed Blind Review

• 1. After you complete the test or question set, immediately check the answers.
  
  
  2. Write down every question that you missed or that you answered correctly but found to be a challenge, but do NOT write down the correct answer.
  
  The first step here is to create a tracking log for each question type. We offer tracker sheets in all of our free LSAT self-study plans, so you can print some of those out or use them as a model for ones you create yourself.
  
  
  3. Next, after taking a break of anywhere from a few hours to a few days, go back and review every question, including the ones you answered correctly. Your goal is to understand the question as well as possible, and to re-answer each question that you missed or felt was challenging.
  
  
  4. As you complete the review of each question, make notes in your tracker as to the broad reason you missed the question, and how to correct that error.
  
  Example: "#7. Didn't ID the causal conclusion. Next time underline the CE indicator."
  
  
  5. If there is any obvious deficiency that's causing you to miss questions in the set you just completed, go study that topic immediately.
  
  For example, let's say that you noticed that you kept mis-diagramming conditional rules in Logic Games. If that's apparent to you, go study that topic right then. The idea is that if you see that something is causing your problems, don't delay in attempting to address it.
  
  
  6. Wait a few days, then redo the questions that you missed or that gave you trouble one more time.
  
  After completing your first delayed review, take a few more days off from studying that particular test or set of problems. Then, after at least three days (but preferably longer), return to the question set and again review any question that was confusing.
  
  
  7. If you still can't answer the problem correctly or figure out what you did wrong, consult an answer source.
  
  After you have given yourself at least two strong looks at the question, if you still do not understand it fully, then consult an external answer resource. That might mean asking your PowerScore LSAT course instructor or tutor, reading the answer explanations in your Online Student Center, looking at one of our publications like the LSAT Deconstructeds or Logic Game Encyclopedias, or posting your question here in our LSAT Discussion Forum.
  
  
  8. Every 10 to 14 days, review your tracker and note the areas where you are having problems. Then restudy the concepts in your course books, in the Bibles, or with your tutor or study group.
  
  
  9. When you run into difficulty, don't panic and don't place undue weight on isolated results.
  
  Your performance will naturally vary, especially as you complete more and more problems and tests. These variances are natural (see my article on The Casino Effect), and you must understand that subtle variations in your performance are natural.
  
  
  10. If you do have a legitimately bad result (such as an unusually low practice test score), don't look at that as the end of the world.
  
  Failure, while not desirable, can provide you with certain benefits. So, if you do suffer a legitimate reversal of fortune (and not just the random kind mentioned in #9), then make sure you get every possible benefit from that failure.

What will happen is a series of benefits: you begin to see your mistakes more clearly and the patterns therein, which can then be attacked, and you also begin to solve problems more quickly and with greater certainty. Forcing yourself to deeply analyze questions gives your mind time to ponder what is occurring, which will help the big concept and strategy blocks fall into place. Having these pieces come together from your own analysis emplaces them far more deeply than if you are told the answer by someone else.

So, back to our question here. In light of the above, what I would say to you is to go back and look at it again. You know answer choice (E) is incorrect. So, can it really be that "E states exactly what the stimulus talks about" ? No, I know we both agree it can't So what are they doing here, and after looking at it, can you tell me why they did it the way they did?

Please let me know what you think and we'll talk about bit in more detail. Good luck!

[biskam]

Is E an issue of Mistaken Reversal of the last sentence in the stimulus? Last sentence: responsible psychologist --> a psychologist who accepts possibility of damning evidence. E: psychologist who accepts possibility of damning evidence --> responsible psychologist. But you can be a psychologist who accepts possibility of damning evidence and NOT be a responsible psychologist.... (Also are always and never SN indicator words? signaling the necessary condition?)

But I'm confused how to figure in "Dr. Ladow's evidence does not conclusively prove that his theory is correct" into the above SN statement. Maybe it's two-pronged? To be a responsible psychologist --> psychologist who accepts possibility of damning evidence AND psychologist's evidence does conclusively prove that theory is correct.

Basically I'm confused how I can prove that B is correct...

Thank you!

[nicholaspavic]

Hi biskam,

In answer to your first question, yes! Answer Option (E) is a mistaken reversal. Well done!

Looking at Anson's argument it is: Responsible psychologist Accept possibility of new evidence showing theories incorrect. So it's not a multiconditional, it's just a straight conditional.

Because this is a Must Be True question we have to find an answer that is a supportable inference from Anson's argument. Answer (B) works well because psychologists working on rat mazes are under the conditional umbrella of all psychologists set up in the stimulus.

Thanks for the great question and I hope this helps.

[biskam]

so am I correct to say that B is the contrapositive of anson's argument!

[James Finch]

Hi Biskam,

Yes, that's correct! (B) is saying:

New evidence could show theories incorrect responsible psychologist