… anecdotal and eyewitness (evidence) are not valid as proof, but in your opinion, can they contribute to a weight of evidence? If not, why not?
You should have listened to my original suggestion.
Which was..?
Go find out, on your own, why it is invalid.
Your claim was that anecdotal and eyewitness evidence is invalid. I am merely attempting to ascertain the basis for your belief in that regard. If you don’t what to - or cannot - tell me, that is fine, but I must state that if you cannot justify a claim you make then we can dismiss it on the grounds that claims made without evidence can be dismissed without evidence.
I don't have the qualifications to explain everything about critical thinking to you.
I am not asking for a philosophical treatise… If you state that eyewitness and anecdotal evidence is invalid, then surely, in consideration that the discussion is about critical thinking, you must have some
reasons on which you base your conclusion? Surely you are not contending that your conclusion is a mere faith based belief?
You are looking for holes in my examples to try and justify the use of anecdotal evidence.
If holes exist, then surely it is legitimate to point them out – that is what critical thinking is all about surely – not accepting things on blind faith, but picking them apart to see if all the underlying assumptions are valid or not? You seemed to have no qualms in suggesting my assessment concerning the matter was incorrect…
By the way, "I saw Jim at the shop today" barely has any value in the first place.
So you say, but I provided an example where it was demonstrably valuable. Do you simply ignore that example or do you have some other objection to it?
It would not trump physical evidence, for example.
I agree, if the physical evidence indicated one thing and the anecdotal evidence another, then the physical evidence is assumed to have the greater weight.
And that's for ordinary claims.
Ummm …for all claims surely?
Can you not see that it is unacceptable, when it comes to ghosts, UFO's and whatnot?
I think you may be confusing evidence with proof. Evidence can constitute proof, but it need not necessarily
be proof. For example, there is the concept of “weight of evidence” we must deal with:
“Weight of Evidence (WOE) … is something widely used both by scientists in evaluating data and in setting regulations and guidelines in the public policy sphere, and is widely understood but is hard to define. Why? Because it calls upon all of one's expertise, training and experience and it addresses all types of issues concerning data big and small. A definition would probably require pages. It is this very imprecision that causes problems in the courtroom: something that is not clearly defined can be defined any way one likes. And so the court tends to avoid weight of evidence testimony and opinions even though they underpin scientific practice.”
(…)
“The argument has been made that weight of five pieces of weak data cannot be turned into a whole of strong data. That mistates the practice and point. 'Weight of Evidence' is somewhat of a misnomer; more accurately it's the fit of evidence that is key rather than its weight. It is how pieces of evidence fit together, complement one another, create a picture larger than themselves that is the determinant, rather than the weight.”(
http://www.toxicologysource.com/law/daubert/judgingthejudges/weightofevidence.html)
I would be interested to hear your opinion on the concept of weight of evidence and any potential role in critical thinking it might play.