Coding Horror

programming and human factors

How Good an Estimator Are You?

Chapter 2 of Software Estimation: Demystifying the Black Art opens with a quiz designed to test your estimation abilities. It's an interesting exercise, so I thought everyone might like to give it a shot.

  • For each question, fill in the upper and lower bounds so that you have a 90 percent chance of including the correct value.
  • Don't make your ranges too narrow or too wide, but be sure they're wide enough to give you a 90 percent chance of hitting the correct value.
  • Don't research the answers on the internet.
  • You must provide an estimate range for each question.
  • Spend no more than 10 minutes on this quiz.

So, how good an estimator are you?

Question Low Estimate High Estimate
Surface temperature of the sun  
Latitude of Shanghai  
Area of the Asian continent  
The year of Alexander the Great's birth  
Total value of U.S. currency in circulation in 2004  
Total volume of the Great Lakes  
Worldwide box office receipts for the movie Titanic  
Total length of the coastline of the Pacific Ocean  
Number of book titles published in the U.S. since 1776  
Heaviest blue whale ever recorded  

Remember, the purpose of the quiz isn't to determine whether or not you're the next Ken Jennings. It's about estimation, not trivia.

Tomorrow, I'll print the answers along with a deeper explanation of this exercise.

Written by Jeff Atwood

Indoor enthusiast. Co-founder of Stack Overflow and Discourse. Disclaimer: I have no idea what I'm talking about. Find me here: