média a posteriori

13:51 May 6, 2013 

Yep, they're usually just used interchangeably but strictly mathematically speaking, there is a subtle difference.

13:49 May 6, 2013 

And I'll never forget the difference between average and mean anymore. :) Thank you and accept my apologies also.

13:47 May 6, 2013 

No problem, I've done the same thing myself :D

This question rang a bell as I translated it in a project a few years back and ended up realizing this term was most standard one.

13:46 May 6, 2013 

It was me. I have erased my comments because I thought it over and maybe I overreacted and it could start an unnecessary argument. You are right, mean is much better than average in this instance and I decided to erase my answer. Thank you for your clarification. All is clear now.

13:41 May 6, 2013 

Some responses appeared here but disappeared; I just wanted to make sure we're on the same page. No offense was meant whatsoever by my disagreement and I apologize for that, but in the end, it's an established mathematical term in English with one correct translation, and a handful of examples of alternate usage do not change this.

It's also a great example IMO of how misleading Google can be, and the fact that it can sometimes "breed" subtle mistranslations. They may not be objectively wrong in the sense that the meaning is unclear, but they are incorrect when there is a standard, accepted option. I'm noting this especially because if the term "PME," which often appears in similar texts.

12:48 May 6, 2013 

Just to be clear about the difference between these, as it's a nice example of why there is more than meets the eye to a Google search. In a case like this, "posterior mean" vs. "posterior average" both "sound" generally correct/interchangeable at first. However, when one turns up 20+ times more results from standard sources, it's a general indicator that this is the more accepted usage.

It's also not a question of "seeing if there are no examples which are not broken sentences." When the top results are primarily made up of these types of hits, with only a handful showing the term itself, it's a sign that this is uncommon usage and probably coming from a prior mistranslation.

Full disclosure, I've seen this term before and have always translated as "posterior mean," which is is particularly important when used with the mathematical term PME, "posterior mean estimate."