How to generate your cubing Confidence Interval!

[Hazel]

Confidence Intervals are a statistical way of showing the margin or error within a group of data. I’m not going to go into too much detail, you can look it up for yourself or take a statistics class in school, but basically, if you have a large session of times in cubing you’ll be able to tell about how fast you are with good accuracy. Sometimes in news articles, you’ll see things like “we are 95% confident that the average amount of [blank] is between 3.46 and 7.89.” That is what you’ll be figuring out, and it’s actually pretty easy. Here’s how:

1. Time yourself on the cube until you have a big session, 500+ solves is probably best. The more solves you have, the more accurate it’ll be. If your times are over ~40 seconds though normally, this method won’t work very well because you’ll be improving a lot over the course of the session.
2. Get yourself a list of all those times so that there’s nothing at all in the list except one time on each line. For example:

7.53
8.93
6.99
7.47
etc.

You can do this easily if you use csTimer by exporting the session to a file, importing it into the Block Keeper timer by @DalDal , then going into settings on Block Keeper and select “remove all formatting in lists”. Press save and click on “Time” in the top-left corner, right above Mo3. Your list will be there, and you can just copy it.

1. Go to this website: http://www.lock5stat.com/StatKey/
2. Click on “CI for Single Mean, Median, St.Dev.” right under the “Bootstrap Confidence Intervals” column.
3. Click “edit data”, remove all the date in the window (control/command F then backspace), then past in your data. Make sure “data has header row” is NOT checked.
4. Click “Generate 1000 samples” at least 5 times, more is better, but you won’t need any more than 10 clicks. Do this slowly if you don’t have a fast computer. It'll probably take some time to load since right now you're computer is doing a lot (really a lot!) of math
5. Check the “Two-Tail” box in the top-left corner of the graph
6. Done! You now have your interval. It’ll be the bottom two values right under the graph in blue. For example, my values are 13.115 and 13.353. This means that I am 95% certain (95% is the default) that the average time it takes me to solve a 3x3 is between 13.115 and 13.353 seconds. Like this
7. Post your results down below, if you like! The correct way to format your findings is like this:

I am 95% confident that the average time it takes me to solve a [puzzle type] is between [lower value] and [higher value] seconds.

One quick thing, if any of your times are over 1 minute you’ll have to change it to seconds for this to work properly (ex. 1:01.93 becomes 61.93)