Re: Optimal Prediction

2002-04-18 Thread Wei Dai
On Mon, Apr 15, 2002 at 04:15:32PM +0200, Juergen Schmidhuber wrote: For example, suppose the process computing the universe is not optimally efficient for some reason. As long as the resource postulate holds the true prior cannot dominate the Speed Prior, and S-based predictions will be

Re: Optimal Prediction

2002-04-15 Thread Juergen Schmidhuber
Wei Dai wrote: BTW, isn't the justification for universal prediction taken in this paper kind of opposite to the one you took? The abstract says The problem, however, is that in many cases one does not even have a reasonable guess of the true distribution. In order to overcome this problem

Re: Optimal Prediction

2002-04-04 Thread Juergen Schmidhuber
Bill Jefferys wrote: At 10:59 AM +0200 4/3/02, Juergen Schmidhuber wrote: The theory of inductive inference is Bayesian, of course. But Bayes' rule by itself does not yield Occam's razor. By itself? No one said it did. Of course assumptions must be made. At minimum one always has to choose

Re: Optimal Prediction

2002-03-29 Thread Bill Jefferys
At 2:39 PM -0800 3/28/02, Hal Finney wrote: Bill Jefferys, [EMAIL PROTECTED], writes: Ockham's razor is a consequence of probability theory, if you look at things from a Bayesian POV, as I do. This is well known in Bayesian circles as the Bayesian Ockham's Razor. A simple discussion

Re: Optimal Prediction

2002-03-29 Thread Hal Finney
From [EMAIL PROTECTED] Fri Mar 29 07:58:20 2002 Resent-Date: Fri, 29 Mar 2002 07:58:29 -0800 Date: Fri, 29 Mar 2002 10:57:49 -0500 To: [EMAIL PROTECTED] From: Bill Jefferys [EMAIL PROTECTED] Subject: Re: Optimal Prediction Resent-From: [EMAIL PROTECTED] X-Mailing-List: [EMAIL PROTECTED

Re: Optimal Prediction

2002-03-29 Thread Hal Finney
Sorry, I mis-edited that message. Here it is cleaned up for clarity: Bill Jefferys writes, quoting Hal Finney: But not always. You give the example of a strongly biased coin being a simpler hypothesis than a fair coin. I don't think that is what most people mean by simpler. If anything,

Re: Optimal Prediction

2002-03-29 Thread Bill Jefferys
At 9:20 AM -0800 3/29/02, Hal Finney wrote: That's true, but even so, a coin with a .95 chance of coming up heads and a .05 chance of coming up tails is simpler by your definition than a fair coin, right? Even though the parameter is not adjustable, the presence of an ad hoc value like .95

Re: Optimal Prediction

2002-03-29 Thread Hal Finney
Bill Jefferys wrote: At 9:20 AM -0800 3/29/02, Hal Finney wrote: That's true, but even so, a coin with a .95 chance of coming up heads and a .05 chance of coming up tails is simpler by your definition than a fair coin, right? Even though the parameter is not adjustable, the presence of an

Re: Optimal Prediction

2002-03-28 Thread Juergen Schmidhuber
Bill Jefferys wrote: At 9:19 AM +0100 3/27/02, Juergen Schmidhuber wrote: You are claiming the AP necessarily implies a specific fact about nuclear energy levels? I greatly doubt that - can you give a proof? Yes, I can.

Re: Optimal Prediction

2002-03-28 Thread Juergen Schmidhuber
Bill Jefferys wrote: It's pointless wasting my time on this. As both Russell and I pointed out, this is a standard example that is cited by people who are knowledgeable about the AP. Either you have a different definition of predictive power than the rest of us do, or you don't understand

Re: Optimal Prediction

2002-03-28 Thread Wei Dai
On Thu, Mar 28, 2002 at 10:44:41AM -0500, Bill Jefferys wrote: It's pointless wasting my time on this. As both Russell and I pointed out, this is a standard example that is cited by people who are knowledgeable about the AP. Either you have a different definition of predictive power than

Re: Optimal Prediction

2002-03-28 Thread Bill Jefferys
At 9:32 AM -0800 3/28/02, Wei Dai wrote: Perhaps you're not familiar with the history of this mailing list, but Juergen Schmidhuber is one of the first authors to explicitly state the idea that all possible universes exist in a published scientific paper, and that paper is cited in the public

Re: Optimal Prediction

2002-03-28 Thread Bill Jefferys
At 6:09 PM +0100 3/28/02, Juergen Schmidhuber wrote: Predictive power is measurable by standard concepts of probability theory and complexity theory. Agreed. You may choose to ignore this, but don't include all those who don't among the rest of us. Write down all assumptions, derive the

Re: Optimal Prediction

2002-03-28 Thread Saibal Mitra
I don't understand this point. Bill Jefferys wrote: Ockham's razor is a consequence of probability theory, if you look at things from a Bayesian POV, as I do. Saibal Mitra

Re: Optimal Prediction

2002-03-28 Thread Hal Finney
Bill Jefferys, [EMAIL PROTECTED], writes: Ockham's razor is a consequence of probability theory, if you look at things from a Bayesian POV, as I do. This is well known in Bayesian circles as the Bayesian Ockham's Razor. A simple discussion is found in the paper that Jim Berger and I

Re: Optimal Prediction

2002-03-28 Thread H J Ruhl
I agree at this point that the AP by itself has no predictive power. My view is that a predictor that currently works in a given universe - say the AP plus other stuff - can not be considered to continue to work. Any universe is subject to true noise either because its rules allow it [type

Re: Optimal Prediction

2002-03-28 Thread Hal Finney
My son was taking a class in college on the philosophy of science. One of the things they talked about was the validity of induction. The basic idea of induction is to identify a pattern and extrapolate it forward. Simplified, induction assumes that the way things have been in the past is the

Re: Optimal Prediction

2002-03-27 Thread Bill Jefferys
At 9:19 AM +0100 3/27/02, Juergen Schmidhuber wrote: Bill Jefferys wrote: At 2:25 PM +0100 3/26/02, Juergen Schmidhuber wrote: But unfortunately the anthropic principle does not have any predictive power. It does NOT predict there won't be any flying rabbits tomorrow. But Hoyle did

Re: Optimal Prediction

2002-03-27 Thread Russell Standish
Juergen Schmidhuber wrote: Bill Jefferys wrote: At 2:25 PM +0100 3/26/02, Juergen Schmidhuber wrote: But unfortunately the anthropic principle does not have any predictive power. It does NOT predict there won't be any flying rabbits tomorrow. But Hoyle did use the AP to

Re: Optimal Prediction

2002-03-26 Thread Bill Jefferys
At 2:25 PM +0100 3/26/02, Juergen Schmidhuber wrote: But unfortunately the anthropic principle does not have any predictive power. It does NOT predict there won't be any flying rabbits tomorrow. But Hoyle did use the AP to predict specific facts about nuclear energy levels, which were

Re: Optimal Prediction

2002-03-26 Thread H J Ruhl
At 3/26/02, you wrote: Normally we do not know the true conditional probability distribution p(next event | past). But assume we do know that p is in some set P of distributions. As I posted earlier my issue with this is how does one know p is in P unless one can compute p, i.e. check it?