Rationality Quotes November 2013

MalcolmOcean

Another month has passed and here is a new rationality quotes thread. The usual rules are:

Please post all quotes separately, so that they can be upvoted or downvoted separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself.
Do not quote from Less Wrong itself, HPMoR, Eliezer Yudkowsky, or Robin Hanson. If you'd like to revive an old quote from one of those sources, please do so here.
No more than 5 quotes per person per monthly thread, please.

Another month has passed and here is a new rationality quotes thread. The usual rules are:

Please post all quotes separately, so that they can be upvoted or downvoted separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself.
Do not quote from Less Wrong itself, HPMoR, Eliezer Yudkowsky, or Robin Hanson. If you'd like to revive an old quote from one of those sources, please do so here.
No more than 5 quotes per person per monthly thread, please.

His stated point is about telling things that everybody is supposed to know.

If you have an SD of 35 for an average of 1362 you have no idea about whether the last digit should be a 2. That means either you do state an error interval or you round to 1360.

Human height changed quite a bit over the last century. http://www.voxeu.org/article/reaching-new-heights-how-have-europeans-grown-so-tall . Taking data about human brainsize with 4 digit accuracy and assuming that it hasn't changed over the last 30 years is wrong.

European gained a lot of bodymass over the last 100 years due to better nutrition. The claim that it's static at 4 digit in a way where you could use 30 year old data to describes todays situation, gives the impression that human brainsize is something with is relatively fixed.

The difference in brain size between Africans and European in brainsize in that study is roughly the difference in height between todays Europeans and Europeans 100 years ago.

Given that background taking a three decades old average from one sample population and claiming that it's with 4 digits accuracy the average that exist today is wrong.

If you have an SD of 35 for an average of 1362 you have no idea about whether the last digit should be a 2. That means either you do state an error interval or you round to 1360.

If individual datapoints have an SD of 35, and you have 20000 datapoints, then the SD of studies like this is 35/sqrt(20000)≈0.24. So giving a one's digit for the average is perfectly reasonable.

17Randaly13y

No, that was absolutely not his point. I don't understand how you could have come away thinking that- literally the entire next paragraph directly stated the exact opposite: [...] More generally, that was not a tightly reasoned book/paper about brainsize. That line was a throwaway point in support of a minor example ("For example, average brain size is not the same in all human populations") on a short blog post. Arguments about the number of significant figures presented, when you don't even disagree about the overall example or the conclusion, are about as good an example of bad disagreement as I can imagine.