Stupid Questions February 2017

Erfeyah

This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.

Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.

To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.

Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.

To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.

Skipping a complicated discussion about many meanings of "probability", yes.

Think about it this way. Someone gives you a box and says that if you press a button, the box will show you either a dragon head or a dragon tail. That's all the information you have.

What's the probability of the box showing you a head if you press the button? You don't know. This means you need an estimate. If you're forced to produce a single-number estimate (a "point estimate") it will be 50%. However if you can produce this estimate as a distribution, it will be uniform from 0 to 1. Basically, you are very unsure about your estimate.

Now, let's say you had this box for a while and pressed the button a couple thousands of times. Your tally is 1017 heads and 983 tails. What is your point estimate now? More or less the same, rounding to 50%. But the distribution is very different now. You are much more confident about your estimate.

Your probability estimate is basically a forecast of what do you think will happen when you press the button. Like with any forecast, there is a confidence interval around it. It can be wide or it can be narrow.