Mar 29

We are going to play a game.

I have three boxes, 1 contains a great prize –let’s say a 3 course meal in a 5 star restaurant. The other 2 contain something evil – let’s say cold tinned spaghetti.

You get to choose 1 box. Take your time. Got it?

I am going to assume you chose box number 2.

I will now tell you that box number 1 contains spaghetti and give you the opportunity to swap your box number 2 for my box number 3.

The question is: should you a) swap, b) not swap or c) it doesn’t matter? More...

Mar 05

In an earlier post, I alluded to the challenge of navigating probabilities when new information comes to hand.

Consider the following scenario:

There is a horrible disease that does something horrible (I won’t be too specific because it is horrible). Its incidence in the general population is 1 in 100,000 (this is pretty rare; less than 250 cases in Australia). There is a screening test which is 100% effective at detecting the disease but has a 1% false positive (i.e. there is a 1% chance it will say you have the disease when you don’t). You have just been screened and have been given a positive result. Should you put your affairs in order? More...