[extropy-chat] silent night

[Eliezer Yudkowsky]

Adrian Tymes wrote:
> --- Harvey Newstrom <mail at HarveyNewstrom.com> wrote:
> 
>> On Dec 26, 2004, at 1:44 PM, Adrian Tymes wrote:
>> 
>>> Absence of evidence is not evidence of absence.

Yes it is.  See the "Law of Conservation of Probability" in the _Intuitive 
Explanation of Bayesian Reasoning_.  If A is evidence for B, not-A is 
necessarily evidence for not-B.

>> I know it's hard to provide evidence of a lack.  But how long do we 
>> wait before beginning to wonder?  After 15 years and still not having
>> a successful review, I am beginning to wonder.
> 
> I agree that there is room for uncertainty.  But if it's been 15 years
> and there really is no substance to this, then why hasn't anyone
> published a disproof? There appears to be neither proof nor disproof -
> and both of those pieces of evidence should be taken into account when
> trying to find the cause. 

If a supposed effect is tested using an experiment of high statistical 
power (that is, high probability of discovering an effect of the given 
magnitude supposing one exists), then the failure of that experiment to 
produce statistically significant results is evidence against the effect. 
This also follows simply from the Bayesian truism that if scientific 
confirmation is evidence for a proposition, then lack of scientific 
confirmation *where a good opportunity exists to confirm* is evidence 
against that proposition.

-- 
Eliezer S. Yudkowsky                          http://singinst.org/
Research Fellow, Singularity Institute for Artificial Intelligence