When to Guess - GMAC's view

These lines are straight from official GMAC literature and might be of some help in deciding when to guess and when to not. I'll post my own thoughts/suggestions on 'Guessing' in a subsequent post. Until then, read on!

"Based on an analysis of thousands of actual GMAT records, the question of whether to guess or leave questions blank (at the end) depends on the number of items you have left, the section you are on (Verbal or Quantitative), and your relative ability. Here is how it breaks down:

• If you only have 1 or 2 items left in either section, it doesn’t make much difference if you guess or omit the question. You should finish the item you are on to the best of your ability and not worry about the others.
  
  
• If you are on the Verbal section, it doesn’t make much difference if you guess when you have up to about 5 questions left. You should finish the item you are on to the best of your ability and not worry about the others.
  
  
• In the Quantitative section, your odds improve if you guess and complete all the questions rather leave the final questions unanswered. After all, there are fewer questions in this section, so each item left blank in this section comprises a higher proportion of the test than in the verbal section. Guess as smartly as you can, but guess nonetheless—do not leave items blank.
  
  
• If you have an idea what your relative ability is ahead of time (i.e., you’ve taken a practice test or diagnostic test), then your guess versus omit strategy differs based on where you think you would fall. If your scores tend to be relatively low on the section, leaving the questions blank may actually result in a higher score than getting even the easy questions wrong by guessing. If you are near the top of the scale, you have farther to fall if you omit the items and therefore you should guess. Low ability—omit; high ability—guess; medium ability—see above."