# Why aren't Bayesian Networks and Variable Elimination introduced earlier?

Throughout my undergrad, I dreaded probability. I hated it, I was horrible in it, I just never got it, and felt stupid when the professors used "summation/marginalization" equations out of the blue to get rid of variables here and there. I just didn't understand it.

When I started my Masters degree, I was dreading that one Statistics/Prob course that I have to take, but then I was introduced to our lord and savior Bayes, and to be specific, Bayesian Networks.

It suddenly all made sense, all these equations that I suffered with, they were mostly variable eliminations on special Bayes Networks. Everything started clicking so much and by the end of the course I was dying to take more prob/stats.

So my questions boils down to, why isn't Bayesian Networks and Variable elimination introduced in undergraduate courses? I've looked at the vast majority of undergrad stat/probability courses in the top 10 us universities and none of them come close to explaining it, even though I feel it makes probability a whole lot easier and understandable!

• I always felt prob/stat was pretty intuitive as is. Maybe your hurdle (and the fix for it) are not common. After all you are generalizing from a sample size of 1. Apr 15, 2018 at 13:21
• It's worth noting that you found it intuitive as a grad student after taking a probability course. Would it be the same if you switched the order?
Apr 15, 2018 at 19:58
• This may be a "monads are burritos" (byorgey.wordpress.com/2009/01/12/…) thing - attributing understanding a concept to the last idea that made it fit into place, rather than the years of struggle that were needed to be ready for that last idea. Apr 16, 2018 at 3:27
• @HenryTowsner Post it as an answer so I can +1 it :) Apr 16, 2018 at 12:37
• As long as you are generalizing from a sample of size 1, A couple of years ago I experimented with using the book "Doing Bayesian Data Analysis" by Krunschke for a Mathematical Statistics course rather than the sort of traditional probability/stats course that I usually use. While the experiment was a partial success, the students still struggled as much as ever and didn't walk around with glowing light bulbs over their heads. Apr 16, 2018 at 12:49