[FRIAM] Screening off

[thompnickson2 at gmail.com]

Frank,  Thanks for sticking with me on this. 

 

My comment was not conceptual, merely algebraic:  Can

 

Pr(R at t3 | I at t2) = Pr(R at t3 | I at t2 & S at t1).

 

…be true if the value of S at t1.is anything other than one?

 

 

 

n

Nick Thompson

 <mailto:ThompNickSon2 at gmail.com> ThompNickSon2 at gmail.com

 <https://wordpress.clarku.edu/nthompson/> https://wordpress.clarku.edu/nthompson/

 

From: Friam <friam-bounces at redfish.com> On Behalf Of Frank Wimberly
Sent: Monday, December 6, 2021 3:07 PM
To: The Friday Morning Applied Complexity Coffee Group <friam at redfish.com>
Subject: Re: [FRIAM] Screening off

 

The question isn't whether 1 has occurred but what is the value of 1 (it's a variable) and is the distribution of 3 is independent of that observed value.

---
Frank C. Wimberly
140 Calle Ojo Feliz, 
Santa Fe, NM 87505

505 670-9918
Santa Fe, NM

 

On Sat, Dec 4, 2021, 5:38 PM Nicholas Thompson <thompnickson2 at gmail.com <mailto:thompnickson2 at gmail.com> > wrote:

Frank, 

 

Still need help. Given events 1, 2, and 3, 3 has been screen off by 2 from 1, if  the probability that 3 occurs given that 2 has occurred is equal to the probability that 3 occurs given that both 2 and one have occurred.     As I understand mathematics this equality requires that the probability of 1 occurring is 1.00.  Another way to say that is that the probability that 3 occurs  if 2 has occurred is the same as the probability that 3 has occurred if 2 has occurred, and 1 has already occurred.  What's the fun in that?  In other words, given the possibility of other causes for 2, the fact that 2 occurs gives us relatively little evidence that 1 has occurred.  Isn"t this true of all causal abduction?  

 

N


.-- .- -. - / .- -.-. - .. --- -. ..--.. / -.-. --- -. .--- ..- --. .- - .
FRIAM Applied Complexity Group listserv
Zoom Fridays 9:30a-12p Mtn UTC-6  bit.ly/virtualfriam <http://bit.ly/virtualfriam> 
un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com
FRIAM-COMIC http://friam-comic.blogspot.com/
archives:
 5/2017 thru present https://redfish.com/pipermail/friam_redfish.com/
 1/2003 thru 6/2021  http://friam.383.s1.nabble.com/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://redfish.com/pipermail/friam_redfish.com/attachments/20211206/55fd15ea/attachment.html>