gwern comments on Value of Information: 8 examples - Less Wrong

48 Post author: gwern 18 May 2012 11:45PM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Article Navigation

Comments (43)
Tags: decision_analysis science practical

Comments (43)

You are viewing a single comment's thread. Show more comments above.

Comment author: Vaniver 26 May 2012 05:29:47PM 0 points [-]

Is there some objective way to confirm that it's not simply reducing your sleep (as a stimulant would) as opposed to improving sleep (and therefore reducing the time you need to spend sleeping)?

Sleep quality is typically measured by "number of times awakened" or "amount moved" or so on- my experience with melatonin (and I believe gwern's as well, but I didn't check) is that melatonin decreases the number of times I awaken during the night.

But even if you measure that, it's just a proxy. A paralytic drug will reduce the amount I toss and turn at night, but may not improve how I feel the next day. What you would want to do is measure energy level / creativity, but that's even more difficult.

Comment author: gwern 26 May 2012 07:57:14PM 1 point [-]

For my melatonin experiment, number of awakenings was 2.86 vs 2.43, but the p-value was only 0.43. The problem is that the standard deviation is 2.25! (On many nights, I awaken zero or one times, but on one particularly bad night, I woke up 7 times.) I suspect more data would show a more reliable effect and maybe a greater effect size than d=0.19.

Comment author: gwern 27 May 2012 02:48:26PM 0 points [-]

To expand; if d<=0.19, to detect this effect at p<0.05 with 75% odds, we need ~75 pairs of nights or ~150 nights of data:

pwr.t.test(d=(456.4783 - (456.4783 - 17.32))/131.4656,power=0.5,sig.level=0.05,type="paired",alternative="greater")
n = 75.44403
d = 0.1911111

Doable, but not trivial.

Powered by Reddit Powered by Reddit