When to NOT answer a PGRE question.

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Discussion Overview

The discussion revolves around the scoring system of the Physics GRE (PGRE), particularly focusing on the implications of guessing versus leaving questions unanswered. Participants explore the advantages and disadvantages of different strategies when faced with questions they may not know how to answer.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants explain that incorrect answers result in a deduction of 1/4 point, while unanswered questions do not incur any penalty.
  • It is suggested that if a participant knows nothing about a question, guessing may not be beneficial, as statistically, it could lead to a net loss of points.
  • Others argue that if a participant can eliminate one or more answer choices, guessing could improve their expected score.
  • One participant expresses confusion about the penalty for leaving questions blank, noting that they are accustomed to tests where attempting an answer is always better than leaving it blank.
  • Another participant clarifies that leaving a question blank is advantageous because it does not count against the test-taker.
  • A participant raises a hypothetical scenario about only answering one question confidently, questioning whether this strategy would be penalized in the scoring process.
  • Further discussion elaborates on the implications of answering only one question correctly while randomly guessing on others, illustrating potential outcomes and scores.

Areas of Agreement / Disagreement

Participants generally agree that leaving questions unanswered does not incur a penalty, but there is ongoing debate about the effectiveness of guessing, especially when considering the elimination of answer choices. The discussion remains unresolved regarding the optimal strategy for answering questions on the PGRE.

Contextual Notes

Some assumptions about the scoring process and strategies for guessing may not be fully articulated, and there are unresolved questions about the implications of answering only a limited number of questions.

teroenza
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Hello. I have a quick procedural question about the physics GRE. I know that incorrect answers deduct 1/4 point from your raw score, but I do not understand how questions that are left unanswered affect you.

Basically I am trying to understand if I have absolutely no idea how to answer a question, whether or not I should guess, or leave it blank.

Thank you
 
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Statistically, if you know *nothing* about a question, guessing will cost you as many points as you gain. (Guess 5 times, hit once, 1 - 4 * 1/4 = 0.) However, if you can eliminate an answer or two, guessing will help you. (If you can eliminate one answer, you'll hit 1 in 4 by guessing, and so 1 - 3 * 1/4 = 1/4.)

If you know absolutely nothing, Dirty Harry has the answer... "Do you feel lucky?"
 
For the expectation value: If you can exclude some value, or at least think that one answer is more likely than another: guess.
Guessing will increase the spread of your expected result - that can be positive or negative, depending on the result you want, and the number of correct answers you find.
 
Thank you both. I think I am confused about the penalty for leaving something blank. I'm used to the standard test where any attempt at an answer is better than a blank, so I don't understand why leaving a question blank would ever be advantageous on the PGRE.
 
There is no penalty for leaving something blank.

The advantage is... a blank answer isn't wrong. :smile:

Statistics says that if you guess at 5 questions with 5 possible answers, you should expect one right on average. However, if you are just guessing randomly, there is a 32.768% chance you'll get them all wrong, and lose 1 1/4 points.

So... do you feel lucky... punk? :smile:
 
This is a stupid question, but I have to ask it. What stops me from answering only one question, that I am absolutely confidant in getting right? Somehow this can't be allowed to happen, so would this process be penalized when the scaled score is computed?
 
teroenza said:
This is a stupid question, but I have to ask it. What stops me from answering only one question, that I am absolutely confidant in getting right? Somehow this can't be allowed to happen, so would this process be penalized when the scaled score is computed?

You would get a 1% score. That doesn't seem very good...
 
teroenza said:
This is a stupid question, but I have to ask it. What stops me from answering only one question, that I am absolutely confidant in getting right? Somehow this can't be allowed to happen, so would this process be penalized when the scaled score is computed?
No one is saying you are graded only on the questions you answer. What they are saying is that you get, say, 1 point if you answer correctly, 0 is you do not answer, and -1/4 point if you answer incorrectly.

If there are 100 question, you answer only one correctly, you get get 1 point, the "1%" micromass gives. If you answer that one question correctly, answer the other 99 completely at random, you would expect to get 99/5= 19.4, which I will round down to 19, correct and 80 incorrect Since you got a total of 20 right and 80 wrong, you will get 20-(1/4)(80)= 0 points.
 
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Thank you very much HallsofIvy.
 

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