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Author Topic:   What is Objective Evidence? (Evidence for More than One)
NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 1 of 18 (100504)
04-16-2004 10:15 PM


This is a spin off from here:
Message 145
Before one arrives at some conclusion it is necessary to gather some evidence. Evidence clearly comes in a wide variety of forms. It also comes in varying levels of quality.
As individuals we have different ways of picking what we take as evidence for anything.
In this topic I would like to discuss what is evidence beyond that which applies to one person. This, obviously to me, includes what would by consensus be called scientific evidence. Is there any other distinct kind?
I think it will come to two kinds; scientific and otherwise with some overlaps or fuzziness. Maybe we'll se otherwise.
To start we should have a few attempts at offering an operational defintion for 'evidence'.
{4/23/04 - Topic title modified from "Evidence for More than One?" to "What is Objective Evidence? (Evidence for More than One)" - Adminnemooseus}
[This message has been edited by Adminnemooseus, 04-23-2004]

Replies to this message:
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 Message 4 by ElliPhant, posted 04-24-2004 8:38 PM NosyNed has replied

  
Adminnemooseus
Administrator
Posts: 3974
Joined: 09-26-2002


Message 2 of 18 (102136)
04-23-2004 6:33 AM


Thread moved here from the Proposed New Topics forum.

  
Loudmouth
Inactive Member


Message 3 of 18 (102259)
04-23-2004 6:16 PM
Reply to: Message 1 by NosyNed
04-16-2004 10:15 PM


quote:
To start we should have a few attempts at offering an operational defintion for 'evidence'.
I think of evidence as something anyone can agree on irrespective of world-view. For example, pretend I have a yellowish/greenish string. I claim that the string is 1.5 meters long and is green in color. I gather 10 people to measure the string and judge it's color. All 10 people agree that the string is 1.5 meters long because length is an objective measurement, and can be used as evidence. However, half the people say the string is yellow while the other half calls it green. This is a subjective measure. However, this subjective measure can also be narrowed down to an objective measure. By measuring the intensity and wavelength of light that reflect off the string I can make an objective measure of its "color". In this way I can relate the color of this string to other strings, unlike using the subjective judgement of color.
What it boils down to is using metrics that do not change, and metrics that can be used between different samples. If the data is presented in such a manner, then the only argument involved is how to interpret the objective evidence.

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ElliPhant
Inactive Member


Message 4 of 18 (102478)
04-24-2004 8:38 PM
Reply to: Message 1 by NosyNed
04-16-2004 10:15 PM


is it possible for evidence to be really objective? As human beings we see what we want to see and what we expect to see, occasionally we see things that stand out because they are different from what we expect to see. We rarely see things that are unnotable and what we are not looking for. Aren't all observations heavily theory dependent?

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berberry
Inactive Member


Message 5 of 18 (102479)
04-24-2004 9:00 PM
Reply to: Message 4 by ElliPhant
04-24-2004 8:38 PM


As I've always understood it, evidence is simply an indication that an idea or a conclusion is correct. It could be anything, but in order for it to be useful (at least for most purposes) it must be widely agreed that it is indeed evidence. Therein lies the rub.

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NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 6 of 18 (102482)
04-24-2004 9:47 PM
Reply to: Message 4 by ElliPhant
04-24-2004 8:38 PM


Believing is Seeing
Carl Sagan said that.
And you're right that is the problem. That is why we don't relay on one person's view to define "objective evidence".
We rarely see things that are unnotable and what we are not looking for.
That is absolutely true. That is why a good researcher is open to those things are unexpected. Discoveries often aren't by big surprises they can be because someone goes "mmm??" at some detail.
Aren't all observations heavily theory dependent?
I would think that it is true that what observations will be attempted are frequently based on theory. That is part of the interplay between theoreticians and experimentalists in physics (e.g.). It is also true that an observation that fits a theoretical framework is probably going to be questioned less than one that doesn't.
The above issues are why you don't see a single experimental result being taken as the last word on anything. Careful replication is an important part of the work.
The scientific process requires rigoruous honesty. That is why there is such a rapid and large consequence if someone violates that. The obsessive scrutiny that interesting results are put under encourages experimenters to be careful.
I was at a talk last fall from the lead physicist who formed the first Bose-Enstein condensate. They spent most of a year after getting it trying to figure what they might have done wrong. Only then did they publish.
{Fixed first quote box - Adminnemooseus}
[This message has been edited by Adminnemooseus, 04-25-2004]

This message is a reply to:
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 Message 7 by ElliPhant, posted 04-24-2004 10:03 PM NosyNed has replied

  
ElliPhant
Inactive Member


Message 7 of 18 (102485)
04-24-2004 10:03 PM
Reply to: Message 6 by NosyNed
04-24-2004 9:47 PM


Re: Believing is Seeing
True, but as pretty much all scientists exist within the same paradigm repeatability of results helps a little but still gets us nowhere near objectivity.

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 Message 6 by NosyNed, posted 04-24-2004 9:47 PM NosyNed has replied

Replies to this message:
 Message 8 by NosyNed, posted 04-24-2004 10:55 PM ElliPhant has replied

  
NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 8 of 18 (102505)
04-24-2004 10:55 PM
Reply to: Message 7 by ElliPhant
04-24-2004 10:03 PM


Re: Believing is Seeing
True, but as pretty much all scientists exist within the same paradigm repeatability of results helps a little but still gets us nowhere near objectivity.
It doesn't? What does? How else would we determine objective facts.
Why do you think repeatability only "helps a little". If there are those who disagree with the results, that is, those whose views would bias against the results, and they repeat the results doesn't that do more than "help a little"? Even if they replicators are operating with the same overall views they aren't just going through the replication for fun. They are trying to see if it does work.
You'd have to show the particular paradigm and how it presents a problem to a particular result to be able to demonstrate that there is a real problem.
The danger of individual bias is, of course, recognized. At any time when there is room for experimentor bias the experimental arrangement should be double blinded. This allows for results to be evaluated without an awareness of how that affects results.
In other cases single blinding is adequate.
Could you explain how the current process only "helps a little" and offer precise examples of the difficulty?

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Replies to this message:
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Coragyps
Member (Idle past 734 days)
Posts: 5553
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 9 of 18 (102508)
04-24-2004 11:18 PM


Let's throw in an example of an observation that is evidence (for something) and is repeatable: a red shift. Anyone with a sufficiently large telescope with a spectrograph attached can point it at galaxies and measure how far the hydrogen-alpha line or a calcium line is from the wavelength a laboratory sample of the appropriate element gives. Henrietta Leavitt, in 1920, got the same numbers by measuring glass photographic plates as we get today with CCDs.
Pretty objective stuff.....
now, the subjective enters later, when Dr Arp disagrees with the other folks, and Dr Humphreys decides that light can "get tired"....

  
ElliPhant
Inactive Member


Message 10 of 18 (102532)
04-25-2004 2:24 AM
Reply to: Message 8 by NosyNed
04-24-2004 10:55 PM


Re: Believing is Seeing
but it isn't necessarily INDIVIDUAL bias. it's PARADIGM bias. which means that no matter how many times you repeat it it's still dependent on the theory that you're looking with, the theory used to build the equipment used to detect your results etc etc etc many many people can all observe the same results, but it still isn't "objective" because they are all wearing the same glasses.
I would argue that absolute objectivity is impossible.

This message is a reply to:
 Message 8 by NosyNed, posted 04-24-2004 10:55 PM NosyNed has replied

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NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 11 of 18 (102539)
04-25-2004 3:15 AM
Reply to: Message 10 by ElliPhant
04-25-2004 2:24 AM


Absolute Objectivity
I would argue that absolute objectivity is impossible.
Sure, I think I agree. But what the heck is "absolute objectivity"? And so what? What does this change?
We do the best we can. When you have some better approach please let me know.

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RAZD
Member (Idle past 1404 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 12 of 18 (102592)
04-25-2004 12:42 PM
Reply to: Message 10 by ElliPhant
04-25-2004 2:24 AM


Re: Believing is Seeing
it's PARADIGM bias. which means that no matter how many times you repeat it it's still dependent on the theory that you're looking with, the theory used to build the equipment used to detect your results etc etc etc many many people can all observe the same results, but it still isn't "objective" because they are all wearing the same glasses.
So the theory influences what is tested ... how does that infulence the result? Taking the redshift experiment from Coragyps:
(http://EvC Forum: What is Objective Evidence? (Evidence for More than One))
The theory could be that there is a blue shift or no shift as easily as that there was a red shift (and in fact red-shift was not expected): how does the expectations influence the actual resulting shift in the element lines of the spectrum? How would it be possible to look at them and conclude a blue shift?
Evidence shows theories to be wrong, and that is when theories get discarded or revised. There are many theories in evolution that have been discarded -- 'Lamarkism' is a well known one, and "the inheritance of acquired characteristics" was part of Darwin's "Origin of Species" -- due to evidence.

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

This message is a reply to:
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Replies to this message:
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ElliPhant
Inactive Member


Message 13 of 18 (102641)
04-25-2004 7:56 PM
Reply to: Message 12 by RAZD
04-25-2004 12:42 PM


Re: Believing is Seeing
theory does influence the results given simply because theory influences the way it's tested.
we don't just LOOK at things anymore. we poke around using instruments. what if it turned out that the theory used to build our telescopes for example, was flawed. this is extremely unlikely and not worth worrying about on a day to day basis. however it is important to know that nothing is EVER tested in isolation, no theory can be extracted from its fellows and tested independently.
sure, most of the time evidence that passes the test of repeatability by different people in different places can be *treated as* being objective. but it still has a possibility of being flawed. it is possible for a hundred people in a hundred different places to all do the same experiment and get the same results (and i've done lab experiments, so them all getting the same results seems highly unlikely, hey the equipment actually working seems highly unlikely) and for every single one of them to be basing it on a flawed assumption.
I'm not saying that science should change, or that there is a better way of deciding which things are good evidence. because I don't think there is one, and if there ever is then I'm sure that that won't be objective either. However, what I am saying is that the dependence of observation on theory should be more widely known, and that science shouldn't take such things like "as close as we can get to objectivity" as "objectivity"

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Replies to this message:
 Message 14 by RAZD, posted 04-26-2004 12:58 AM ElliPhant has replied
 Message 15 by crashfrog, posted 04-26-2004 1:49 AM ElliPhant has replied

  
RAZD
Member (Idle past 1404 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 14 of 18 (102698)
04-26-2004 12:58 AM
Reply to: Message 13 by ElliPhant
04-25-2004 7:56 PM


restating is not reinforcing
all you have done is restate your previous opinion.
please explain how a theory on redshifting would change the appearance of the evidence?

we are limited in our ability to understand
by our ability to understand
RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

This message is a reply to:
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crashfrog
Member (Idle past 1466 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 15 of 18 (102710)
04-26-2004 1:49 AM
Reply to: Message 13 by ElliPhant
04-25-2004 7:56 PM


we don't just LOOK at things anymore. we poke around using instruments. what if it turned out that the theory used to build our telescopes for example, was flawed.
Then we'd know our eyes didn't work either, because they're based on the same optical principles. If everybody's eyes are "broken" in the same way, then you're back to the problem of not knowing if there's really a reality or not, but being unable to discern any kind of difference.
A difference that is no difference is no difference. You're wondering if instrumentality is as valid a method of observation as our own senses, but ignoring the fact that our own senses are also instruments.
Observation is theory-laden, but not in the way I think you think. Theory shouldn't affect the outcome of an observation, if you're observing properly, but theory can affect the observations you choose to make.

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Replies to this message:
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