The Amazing Shrinking Sermon

A Church article with View Comments posted 3 July 2010.
Tags:

San Ignacio Church's Pulpit

In early October 2002, I was both a smart alec undergraduate doing a minor in Mathematical Statistics and the guy at church who was recording sermons to put them on the internet. I noticed over a span of six weeks that Pastor’s sermons were getting progressively shorter each week. Taking to heart the saying Mark Twain popularized, that “there are three kinds of lies: lies, damned lies, and statistics,” I thought I’d apply some intentionally faulty reasoning and write it up for fun.

I stumbled upon it recently while cleaning up some old computer files, and it shows something very important about trusting models. More on that below.

Keep reading…

The Statistics of Chutes and Ladders

A Tech article with View Comments posted 7 July 2009.
Tags: ,

Seeing this node on Chutes and Ladders over at PerlMonks, I thought it would be interesting to throw my hat into the ring. Chutes and Ladders can be represented as a time-homogenous Markov chain with 100 possible states. Each state transition can be represented in a matrix (size 100×100) of transition probabilities T, where T_ij is the probability of transitioning from state i to state j. Then you represent the probability of being in a certain state after a transition as the 1×100 matrix P, where for the beginning of the game (P_0) the first entry is 1 and the other ninety-nine are 0.

Keep reading…