Tim Richardson

Melbourne, Australia

  • Increase font size
  • Default font size
  • Decrease font size

Quiz Results

E-mail Print PDF

Quiz results

You should read this page only after taking the over-confidence test. 

If you want to do this in the recommended order, start here (to read about how the quiz works)

 You can jump straight to the quiz:

  http://tim-richardson.net/misc/estimation_quiz.html

Choose "read more" when you are ready.

The test does not guage what you know, but your evaluation of what you know. 

You were invited to choose a range aiming for a 90% chance of getting each question right.

The questions were chosen by professional researchers (not by me). The point is that they are questions to which most people have little idea what the exact answer is, but most people should be capable of estimating an answer. The questions are quite cunning; they refer to things which you some experience with. And that's exactly the type of estmating we have to do in real life.

It's up to you to choose a range which you think includes the correct answer. You were given a blank cheque (check) ... and how did you spend it?

If you really gave your self a 90% of chance of getting each one correct, then 94% of the time, you would get at least 8 correct.

This probably isn't what happened, though. We seem to be biased towards over confidence. Most people do shockingly badly; we know we don't know the exact answer, but we're pretty sure about approximately what the the correct answer is, and we're too proud to take the easy way out and guess that the answers are between 0 and 999,999.

There is a discussion of this on page 139 of The Black Swan by Nassim Taleb. (buy with free shipping worldwide)

This test comes from

Confident Decision Making, J. E. Russo & P. J. H. Schowmaker, 1989, Piatkus, London p 71

So the test predates the (first) dot com crash and the financial meltdown.

Comments (3)
  • Jon Ericson  - Perhaps not the best questions
    avatar
    I got 8 correct, but I think it was more a matter of luck than confidence. The trouble with this particular set of questions is that too many of them require context that may or may not be available. For instance, I remembered that MLK and Kennedy are often linked because they were assassinated at a young age. But for the various sizes and weights, I had almost no context for. (The Nile question is literally impossible to answer unless I know what size ruler used to measure.) Mozart birth year I knew, but for the elephant gestation period I only had human gestation to compare it to. (Turns out that doubling the human period is too short. Who knew?)

    Not that I have any suggestions besides using a wider variety of questions. (At least three of the questions are easier to get if you know the diameter of the earth.)
  • Anonymous
    avatar
    Hi Jon, i think that you missed the point of the exercise
  • Vanessa Uterreiner  - NOt sure I agree...
    avatar
    I only got 1 right but I am not sure that proves I am over confident. I really had no idea and guessed aimlessly at numbers and stuff. That math with the 90% alone lost my interest and when I read the questions and realized I had no shot of knowing the answers made me feel very dumb and not confident at all. Maybe I too missed the point, but I don't think so. Maybe questions that I might possibly learned at some point I may feel confident than, but I already know that a low self-confidence is part of my problem. I do not think this is an accurate assessment....what do I know though. I am just a student.
Write comment
Your Contact Details:
Gravatar enabled
Comment:
Security

Add this to your website
Last Updated on Monday, 31 October 2011 22:34