On the nature of evidence

[Ivor the Engineer]

No. A null hypothesis that's true has only an alpha probability of being rejected regardless of the sample size because the sample size is taken into account when making that determination.

<snip>

How often is the bolded section true for two (or more) populations being compared in the real world?

 

[Ivor the Engineer]

Double Post.

 

[Dr H]

eta : If I saw a fairy I'd cut back on the beer.

For myself, I find that beer makes the fairies go away.

 

[Dr H]

But that's putting the conclusion before the evidence. It's starting with the assumption that fairies don't exist and therefore the evidence can't be in support of it. If fairies did exist, seeing one would be evidence for it, surely?

Your proposition makes the same assumption -- you are starting with the assumption that fairies do exist, and then asserting the seeing a fairy is therefore supporting evidence for that assumption.

Better to start with no assumptions, and let the evidence lead where it will.

For example: you say "I saw a fairy." My most sensible response would be to say "please explain what you mean by 'a fairy'," and then take it from there. Carefully defining the key terms in a claim could well result in connections with other pre-existing evidence. If you describe what you mean by "a fairy," and it turns out to match the description that I and others use when we see a blue Lexus, that prior information contributes to the interpretation that I make of the evidence you have given me.

The same would be true if your description of "a fairy" seems to match the description I and others have for Tinkerbell, though in that case I'd probably make a somewhat different interpretation of the meaning of your evidence.

Now, it is incredibly unlikely that fairies exist, however if science is about accumulation of relative evidence then claiming something is not evidence simply because we have already concluded it isn't real is putting the cart before the horse.

Assigning something a probability based upon extant evidence to date isn't the same thing as coming to a fixed and dogmatic conclusion. At any rate, it is evidence; it's just not strong evidence for the general existence of fairies.

I guess it comes down to agreeing whether an observation can only be evidence for one thing or for many other things.

An observation, like any other piece of evidence, can be evidence for more than one thing. Experience seems to show that it will be stronger evidence for some things than for others.

Seeing Tinkerbell might be strong evidence for you that Tinkerbell-like fairies exist; it would be less strong evidence of such for me, because for me it is not an observation, but merely an anecdotal report. OTOH, as previously noted, it would be reasonably strong evidence for me that you wanted me to believe that you had seen something that, for whatever reason, you associated with fairies.

If we had been sampling wild mushrooms prior to your disclosure, it might also be reasonably strong evidence that one of us, at least, had found some good mushrooms.



Athon[/QUOTE]

 

[schlitt]

In my opinion evidence is made from units of information placed in a context where the sum conclusion drawn from a consistency of interaction between each relating part indicates a relation to a larger context’s conclusion, which is an objective account of a material happening.

The key with evidence is relating information, and the cause and effect links between each separate component and the need for consistency between each separate possible interaction at every step.

Where I think different conclusions can be drawn by examining the same evidence can be put down to errors in the information linking stage. Missing necessary units of information (gap in knowledge), or making an error of inconsistency between relating/interacting integral units, or missing the link of known informational units altogether. A form of the latter is cognitive dissonance, but I think cognitive ability in this process of information linking goes deeper than that, to the point of capability for the physical system of matter itself (one's brain).

 

[Beth]

How often is the bolded section true for two (or more) populations being compared in the real world?

Depends on the hypothesis. You have a valid point regarding common tests, but there are other types of hypotheses that don't have that problem.

 

[Dr H]

Yet science is based on accumulating evidence. Imagine it slightly different - a new particle in physics where one should not exist. To start with the assumption it cannot exist, therefore it can't be evidence for one risks missing out on a novel discovery. If such a particle did exist, observing it would be evidence of it. The inference of 'novel particle' is only dismissed as a result of applying Occham's Razor, and not because the observation is not evidence for it.

Science doesn't progress by flinging out hypotheses willy-nilly where none are needed and then trying to prove or disprove them. Hypotheses come into play when we believe or discover that our current explanation for an existing observation is either incorrect or incomplete.

A new particle in phyiscs would be hypothesized to explain an existing observation -- e.g., "I observe the action of gravity, and I wonder 'how does gravity propogate?' Maybe there's a particle which carries the gravitational force, which I'll call the graviton."

Or perhaps I note that the gamma ray energy measured from a high energy electron/positron collision doesn't fully account for that predicted by the current mathematical model, so I postulate that some of the energy is going into the creation of a new particle, the neutrino.

In either case, pre-existing observation provided a logical reason for hypothesizing the new particle, and I then go and test the hypothesis. Unless involved in writing fiction, a physicist isn't likely to be sitting around and for no good reason suddenly announce he's going to begin searching for "darkons" or any other particle for which observation hasn't already suggested the possibility.

 

[Dr H]

You can't prove a negative universal statement.* But you can't prove a positive universal statement either. Rather than saying you can't prove a negative, a statement which only applies to some negative statements (but people will misconstrue as applying to their particular negative statement, thereby rendering it safe), it makes more sense to say that you can't prove a universal statement (excluding those that represent definitions/tautologies). Otherwise you are forced into a corner where you ignore the normal process of science (which is generally not about universal statements) or you tie yourself into philosophical knots trying to fit a large, mammalian quadruped in the space behind the bookcase.

Yes. I was hoping somebody was going to get around to saying this.

The rules of the Aristotelian logic on which we base our scientific epistemology specify that a positive assertion needs to be backed by evidence. An assertion without basis -- not backed by evidence--is by default taken to be unproven. In order to prove or disprove an assertion the assertion must contain enough specification so that we can seek evidence about the statement, be it supportive evidence or contradictory evidence.

Given such specificity, one can most certainly prove many positive and many negative assertions. But once there is specificity, we have eliminated universality -- and it is the
universal assertions -- positive or negative -- which are unprovable.

Viz.: given a standardized definition for "unicorn" I can prove to any level of detail required that there are NO unicorns in the room I now occupy. OTOH, I cannot prove that no unicorns exist anywhere in the universe.

 

[athon]

Your proposition makes the same assumption -- you are starting with the assumption that fairies do exist, and then asserting the seeing a fairy is therefore supporting evidence for that assumption.

Better to start with no assumptions, and let the evidence lead where it will.

I'm not sure what you mean by that. It's impossible to not speculate on what an observation might relate to, which is essentially what we are doing.

As I've admitted, a better way of going about it is saying the observation is 'I saw a small flying man', and then speculating 'It could be a fairy'. Indeed, what I'm arguing is that seeing little flying men is evidence of fairies, even if it alone is not good evidence.

Many skeptics are quick to suggest a sighting of a little flying man is not evidence at all, as fairies do not exist. I'm suggesting that in a situation where fairies did exist a sighting of a flying man would be evidence of it. Science more or less says 'if X were true, then we'd observe Y'.

For example: you say "I saw a fairy." My most sensible response would be to say "please explain what you mean by 'a fairy'," and then take it from there. Carefully defining the key terms in a claim could well result in connections with other pre-existing evidence. If you describe what you mean by "a fairy," and it turns out to match the description that I and others use when we see a blue Lexus, that prior information contributes to the interpretation that I make of the evidence you have given me.

Ok, so you haven't been following the thread. Darat pointed this out, and I fully agree.

Assigning something a probability based upon extant evidence to date isn't the same thing as coming to a fixed and dogmatic conclusion. At any rate, it is evidence; it's just not strong evidence for the general existence of fairies.

Again, my point exactly. Skepticism is based on the very notion of probability over certainty, with a view that conclusions can always be changed if presented with evidence. I'm not suggesting such a sighting is good evidence, or even that it would necessarily lead to overturning other models which explain the observation. I am suggesting that it is evidence, though, and the use of the term - especially when skeptics are fond of saying 'you have no evidence' - is at best misleading, and at worst wrong.

If we had been sampling wild mushrooms prior to your disclosure, it might also be reasonably strong evidence that one of us, at least, had found some good mushrooms.

No argument here.

Science doesn't progress by flinging out hypotheses willy-nilly where none are needed and then trying to prove or disprove them. Hypotheses come into play when we believe or discover that our current explanation for an existing observation is either incorrect or incomplete.

I agree, however I'm thinking your 'where none is needed' is a strawman in this situation.

Observing a winged flying man is technically an anomalous observation. Unlike observing a flying feathered animal, taking the observation at face value and slotting it into an existing model isn't so simple. It is therefore assume to be related to a hoax or a hallucination. There is ample evidence to show this is more likely than the observation being a genuine sighting of a mythological creature. Yet the observation is still an anomaly, so there is no flinging an hypothesis out 'willy nilly'.

To use an historical example, germ theory in the 19th century presented the novel idea of bacteria causing fermentation, rather than simply being present. Miasma theory was the accepted paradigm and explained most observations well, including the presence of bacteria (which many accepted were merely like scavengers at the scene of decay). According to you, suggesting that bacteria caused fermentation would be throwing an hypothesis out 'willy nilly'. Instead, it was a question which resulted in experimentation ultimately leading to modern germ theory.

Asking 'what if...' about anomalous observations, even while we have good models which can explain it, is what makes science better than religion.

A new particle in phyiscs would be hypothesized to explain an existing observation -- e.g., "I observe the action of gravity, and I wonder 'how does gravity propogate?' Maybe there's a particle which carries the gravitational force, which I'll call the graviton."

Or perhaps I note that the gamma ray energy measured from a high energy electron/positron collision doesn't fully account for that predicted by the current mathematical model, so I postulate that some of the energy is going into the creation of a new particle, the neutrino.

In either case, pre-existing observation provided a logical reason for hypothesizing the new particle, and I then go and test the hypothesis. Unless involved in writing fiction, a physicist isn't likely to be sitting around and for no good reason suddenly announce he's going to begin searching for "darkons" or any other particle for which observation hasn't already suggested the possibility.

I might have been unclear. That, and particle physics isn't my background so I can't say for certain whether observing a new particle with unusual properties without having actively searched for it is even possible (although I'd be surprised if it wasn't). However in fields I am familiar with, unexpected observations which don't fit easily into an existing model are often enough to inspire one to consider the implications of modifying existing models or creating entirely new ones.

Athon

 

[Darat]

...snip...

I agree, however I'm thinking your 'where none is needed' is a strawman in this situation.

Observing a winged flying man is technically an anomalous observation. Unlike observing a flying feathered animal, taking the observation at face value and slotting it into an existing model isn't so simple. It is therefore assume to be related to a hoax or a hallucination. There is ample evidence to show this is more likely than the observation being a genuine sighting of a mythological creature. Yet the observation is still an anomaly, so there is no flinging an hypothesis out 'willy nilly'.

...snip...

Isn't this the crux of an issue we often see here being argued by the believers in something that is "anomalous"? It shows up in many forms two of the most common are "science has been wrong before" or "they laughed at Galileo".

I touched on why I think this is erroneous in a previous post and it boils down to the fact that your sighting of the "winged flying man" is not an anomalous observation given our current working models, indeed our current models predict that people will have such sightings.

So there is no need to consider or think up a new hypothesis (one that means the current model which rules out "winged flying men" has to be discarded) to explain the sighting. The current model gives us quite adequate explanations, such as you were simply mistaken, you are lying, it was a hoax and so on. In other words the sighting does not give us any reason to consider an alternate hypothesis that states "fairies [can] exist".

I think this is a point that some people who have certain anomalous beliefs (I quite like that phrase it seems less antagonistic than others used here) really struggle to understand. And it takes us back to the "extraordinary claims..." concept, it's not only a requirement for the claim to be accepted but in many cases we require "extraordinary evidence" before we even have a reason to consider the alternative hypotheses anomalous believers put forward.

 

[SirPhilip]

For me I use "evidence for/against A" to describe E if over random observations R,

What does ">>" mean here? It means something like "significant enough that taking note of things like E is a more efficient way to arrive at the truth about A than most alternatives". In reality the right hand side should be "> 0" but in practice we only have a certain amount of computational resources, so taking note of everything is a far worse plan than only taking note of "significant" things.

Thanks for the laughs, Greedy.

 

[SirPhilip]

This topic seems to crop up every now and then

And now it's your fault..

This relates to recent discussions on 'opinions' which Msr Larsen has been struggling with.

I believe Mr.Larson is in fact male, despite evidence to the contrary.

I put forward that not all opinions are equal, and that even claims on personal taste could be supported with evidence should the situation ever call for it. Retreating to the statement that a belief is 'just an opinion' does not automatically absolve one of needing to provide evidence (even if requiring evidence on some opinions might be incredibly pedantic).
What is your definition of 'evidence'? Does it only exist in conjunction with what we currently know in the universe? Is seeing a fairy evidence for fairies?

The ability to make reasoned judgments is just due to an absence of prejudice (a self-centered coping mechanism people commonly develop to avoid psychological distress). It's really as simple as that.

 

[Dr H]

Your proposition makes the same assumption -- you are starting with the assumption that fairies do exist, and then asserting the seeing a fairy is therefore supporting evidence for that assumption.

Better to start with no assumptions, and let the evidence lead where it will.

I'm not sure what you mean by that. It's impossible to not speculate on what an observation might relate to, which is essentially what we are doing.

Excuse me if I misunderstood you. What you seemed to be saying was that if one holds that a reported fairy sighting is not good evidence for the existence of fairies, that one is necessarily assuming a priori that fairies don't exist. Yet then you said "If fairies did exist, seeing one would be evidence for it, surely?" -- which appeared to me to be an a priori assumption that fairies do exist.

All I did was point out that the two assumptions constitute the identical sort of error. Speculation is fine, but when it reaches the point of presupposing a result, one can start digging around for evidence to fit the explanation, rather than an explanation to fit the evidence. That sort of cherry-picking of data is antithetical to science.

As I've admitted, a better way of going about it is saying the observation is 'I saw a small flying man', and then speculating 'It could be a fairy'. Indeed, what I'm arguing is that seeing little flying men is evidence of fairies, even if it alone is not good evidence.

Many skeptics are quick to suggest a sighting of a little flying man is not evidence at all, as fairies do not exist. I'm suggesting that in a situation where fairies did exist a sighting of a flying man would be evidence of it. Science more or less says 'if X were true, then we'd observe Y'.

SINOs -- skeptics in name only.

There are a lot of knee-jerk cynics parading around as skeptics; the Usenet newsgroup sci.skeptic is heavily populated with them. They do more harm than good to the cause of critical thinking.

Assigning something a probability based upon extant evidence to date isn't the same thing as coming to a fixed and dogmatic conclusion. At any rate, it is evidence; it's just not strong evidence for the general existence of fairies.

Again, my point exactly. Skepticism is based on the very notion of probability over certainty, with a view that conclusions can always be changed if presented with evidence. I'm not suggesting such a sighting is good evidence, or even that it would necessarily lead to overturning other models which explain the observation. I am suggesting that it is evidence, though, and the use of the term - especially when skeptics are fond of saying 'you have no evidence' - is at best misleading, and at worst wrong.

Again, I appologize if I addressed your critique of the attitude of some "skeptics" as if you were offering it as your own view. In your original post you seemed to be questioning the definition of "evidence," and my point is that the issue is probably not one of defining that word, so much, as of being able to critically examine evidnece to determine how strong (or weak) is may be.

There is a popular notion among certain non-skeptics, for example, that if you have a whole lot of weak evidence, it somehow magically adds up to strong evidence for whatever nostrum they happen to want to promote. Homeopathy furnishes a great example: I've seen it frequently argued that because a lot of people who use homeopathic remedies think that they have worked, this is therefore powerful evidence that the remedies DO work. It has proven pretty much useless to point out that just because a lot of people also once believed that the Earth was flat doesn't mean that the Earth really was flat at some time in the past.

Science doesn't progress by flinging out hypotheses willy-nilly where none are needed and then trying to prove or disprove them. Hypotheses come into play when we believe or discover that our current explanation for an existing observation is either incorrect or incomplete.

I agree, however I'm thinking your 'where none is needed' is a strawman in this situation.

Actually it's crucial to my point: scientific hypothesis follows observation. There is no need to formulate an hypothesis for an imaginary phenomenon.

To use your example: unless there were other, pre-existing reasons to believe that fairies might exist, one person's reported observation of Tinkerbell is not necessarily evidence that fairies exist. At best, it is evidence that some unexplained phenomenon may exist, which that person claims to have observed.

To use my example: a physicist wouldn't postulate a new particle unless there were other observations or mathematical evidence to suggest that such a particle might help to explain some currently unexplained phenomenon. Lacking that necessity, it's highly doubtful that said physicist is just going to jump out of bed one morning, declare "hey, wouldn't it be cool if there were Purple Particles!" then jog down to the cyclotron and start smashing atoms
hoping to find a purple-on.

Observing a winged flying man is technically an anomalous observation. Unlike observing a flying feathered animal, taking the observation at face value and slotting it into an existing model isn't so simple. It is therefore assume to be related to a hoax or a hallucination. There is ample evidence to show this is more likely than the observation being a genuine sighting of a mythological creature.

Yes -- and the key here is that there is "ample evidence" -- pre-existing data and observation--which can be brought in to inform the interpretation of the anomalous observation.

Yet the observation is still an anomaly, so there is no flinging an hypothesis out 'willy nilly'.

That "willy-nilly" was directed at your suggestion that a scientist had to pre-assume the existence of undiscovered particles and then go looking for them, which seemed to me to be wandering off the track of scientific method by putting the explanation before the observation. Regrets if I misconstrued your intended meaning.

To use an historical example, germ theory in the 19th century presented the novel idea of bacteria causing fermentation, rather than simply being present. Miasma theory was the accepted paradigm and explained most observations well, including the presence of bacteria (which many accepted were merely like scavengers at the scene of decay). According to you, suggesting that bacteria caused fermentation would be throwing an hypothesis out 'willy nilly'.

Not at all. There was an observed phenomenon -- fermentation. Existing theory left a great deal of the process unexplained, so there was ample reason to seek new hypotheses which would better explain it. This is not the same as, say, forming an hypothesis that unicorns are sensitive to human pheremones and that's why they prefer virgins, and then using that as a basis for going out hunting unicorns.

You see what I'm saying, or am I still being unclear?

Asking 'what if...' about anomalous observations, even while we have good models which can explain it, is what makes science better than religion.

Absolutely.

I might have been unclear. That, and particle physics isn't my background so I can't say for certain whether observing a new particle with unusual properties without having actively searched for it is even possible (although I'd be surprised if it wasn't). However in fields I am familiar with, unexpected observations which don't fit easily into an existing model are often enough to inspire one to consider the implications of modifying existing models or creating entirely new ones.

Again, no argument.

I begin to suspect we have simply been on different parts of the same page.

 

[athon]

Excuse me if I misunderstood you. What you seemed to be saying was that if one holds that a reported fairy sighting is not good evidence for the existence of fairies, that one is necessarily assuming a priori that fairies don't exist. Yet then you said "If fairies did exist, seeing one would be evidence for it, surely?" -- which appeared to me to be an a priori assumption that fairies do exist.

I apologise for the confusion. I did try to make clear that this wasn't about whether evidence was 'good' or not, but rather whether it could be called evidence at all.

All I did was point out that the two assumptions constitute the identical sort of error. Speculation is fine, but when it reaches the point of presupposing a result, one can start digging around for evidence to fit the explanation, rather than an explanation to fit the evidence. That sort of cherry-picking of data is antithetical to science.

I agree, however in seeking an inference to explain the observation, it can't be helped to speculate 'if X exists, then this observation would also occur'. The cherry picking occurs when only supportive observations are selected in favour of X and contrary observations are ignored.

SINOs -- skeptics in name only.

There are a lot of knee-jerk cynics parading around as skeptics; the Usenet newsgroup sci.skeptic is heavily populated with them. They do more harm than good to the cause of critical thinking.

I've started to give up on the term skeptic, as I can't define it. It becomes something of a Scottsman fallacy when you try to sort people into being a skeptic or pseudoskeptic. What I was more referring to is self-proclaimed skeptics - I wonder sometimes if there is a correlation between such knee-jerk reactions and how loudly somebody advertises their skepticism.

Again, I appologize if I addressed your critique of the attitude of some "skeptics" as if you were offering it as your own view. In your original post you seemed to be questioning the definition of "evidence," and my point is that the issue is probably not one of defining that word, so much, as of being able to critically examine evidnece to determine how strong (or weak) is may be.

No need to apologise. I wouldn't have put it up if not seeking good criticism of my point and my articulation of it. I know many might find the question pedantic, however I have a great interest in precisely how science language is used amongst a demographic.

Actually it's crucial to my point: scientific hypothesis follows observation. There is no need to formulate an hypothesis for an imaginary phenomenon.

To use your example: unless there were other, pre-existing reasons to believe that fairies might exist, one person's reported observation of Tinkerbell is not necessarily evidence that fairies exist. At best, it is evidence that some unexplained phenomenon may exist, which that person claims to have observed.

I'm not sure why you make the distinction of claiming that it's safe to say one can make a claim that an unexplained phenomenon might exist, yet that unexplained pheomenon could not possibly be a fairy.

I might interject my own argument here for a moment and move my own goal posts intentionally, if I may - I recognise now that the example I used has a large problem. Fairies aren't a model in themselve explaining a flying humanoid; there is no single, straight forward criteria explaining what one means. Indeed, it's probably one of the biggest holes many paranormalists and faithers fall into (definining their model with any precision).

Sorry if somebody has already pointed that out to me and I didn't get it.

My original question of defining evidence still stands, however I really need to reconsider another example.

To use my example: a physicist wouldn't postulate a new particle unless there were other observations or mathematical evidence to suggest that such a particle might help to explain some currently unexplained phenomenon. Lacking that necessity, it's highly doubtful that said physicist is just going to jump out of bed one morning, declare "hey, wouldn't it be cool if there were Purple Particles!" then jog down to the cyclotron and start smashing atoms hoping to find a purple-on.

Again, I'm assuming you have more particle physics experience than I do. Would it not be possible (if unlikely) to see the results of a particle collision and witness, say, two particles where your maths initially only counted for one? Have there never been moments in science history where an unexpected observation with no immediately recognisable relationship to accepted models has resulted in the support of a weaker model?

Yes -- and the key here is that there is "ample evidence" -- pre-existing data and observation--which can be brought in to inform the interpretation of the anomalous observation.

This seems somewhat chicken and egg, then. Remember, I'm not qualifying it as good evidence - just defining the observation as 'evidence' or 'not evidence'. If you have no pre-existing evidence at all for a model, then there is going to have to be a first observation which inspires the speculation. Indeed, we both agree it would be far from sufficient to accept the model, but it still must be considered evidence in order for it to accumulate.

That "willy-nilly" was directed at your suggestion that a scientist had to pre-assume the existence of undiscovered particles and then go looking for them, which seemed to me to be wandering off the track of scientific method by putting the explanation before the observation. Regrets if I misconstrued your intended meaning.

Not at all. I remind you I'm not a particle physicist, so could be butchering their craft big time. I'm picturing a possibly fantasy situation where a particle is smashed, numbers are crunched, particles counted and something comes up amiss, leading in itself to then speculating if an anomalous result is a new phenomena. Of course chances are low, but I would find such a situation (if even possible) where such a speculation is not even considered to be somewhat against how science works.

Not at all. There was an observed phenomenon -- fermentation. Existing theory left a great deal of the process unexplained, so there was ample reason to seek new hypotheses which would better explain it. This is not the same as, say, forming an hypothesis that unicorns are sensitive to human pheremones and that's why they prefer virgins, and then using that as a basis for going out hunting unicorns.

You see what I'm saying, or am I still being unclear?

More like I'm being daft. It's cool.

I'm not in 100% agreement with your view that at the time, there was the sentiment that the existing theory left a great deal of the process unexplained. While particle physics isn't my field, science history is - and it was far from black and white in terms of any acceptance of the necessity for novel explanations. Many at the time felt fermentation was merely a chemical reaction, and the presence of replicating life forms was coincidence. For many, there was no need to ask how it started (you do have to bear in mind that reductionism as we understand it today wasn't a strong driving force behind discoveries in the past. People were satisfied with 'it just is'. Mind you, many of the greatest discoveries were made by vitalists and the like who were happy with such answers).

I begin to suspect we have simply been on different parts of the same page.

No, I owe you a big thanks for the criticisms, even if we ultimately agree. While I might be 'right' overall (by populat agreement), I still like to clarify my personal understanding of the details.

Athon

 

[Dr H]

I apologise for the confusion. I did try to make clear that this wasn't about whether evidence was 'good' or not, but rather whether it could be called evidence at all.

Not to put too fine a point on it, my answer to that is "yes, of course it can be considered evidence." For me, that's the easy part. The more serious considerations are "evidence for what?" and "of what quality is the evidence for that conclusion?".

I agree, however in seeking an inference to explain the observation, it can't be helped to speculate 'if X exists, then this observation would also occur'. The cherry picking occurs when only supportive observations are selected in favour of X and contrary observations are ignored.

No argument.

I've started to give up on the term skeptic, as I can't define it. It becomes something of a Scottsman fallacy when you try to sort people into being a skeptic or pseudoskeptic. What I was more referring to is self-proclaimed skeptics - I wonder sometimes if there is a correlation between such knee-jerk reactions and how loudly somebody advertises their skepticism.

A matter of personal taste, perhaps. "Skepticism" to me is the epistemological position that claims or assertions of knowledge must be testable and supported by hard evidence, and that knowledge is conditional, not absolute, and therefore subject to evolution and refinement based upon the amount and kind of evidence available.

"Psuedoskeptics" do exist, but I find that term so vastly overused by the woo-woo crowd that in many contexts it is all but meaningless.

No need to apologise. I wouldn't have put it up if not seeking good criticism of my point and my articulation of it. I know many might find the question pedantic, however I have a great interest in precisely how science language is used amongst a demographic.

I am also interested in language usage. I have seen many arguments derailed to the '◊◊◊◊ YOU TOO!' stage when one party was simply insisting on coherent definitions fo key terms, and the other was convinced they were dodging the real issues with "semantic games."
Semantics are important: they are how we communicate. When we do. ;-)

I'm not sure why you make the distinction of claiming that it's safe to say one can make a claim that an unexplained phenomenon might exist, yet that unexplained pheomenon could not possibly be a fairy.

Because the first is a simple acknowledgement of anomalous data -- or evidence, if you will -- whereas the other represents an interpretation of that data. Once one begins interpreting data one is no longer a neutral observer. At some point, of course, interpretation has to occur, but if it is brought in prematurely it can bias the collection of additional data -- e.g., instead of simply collecting additional data and examining it to see what sort of patterns may emerge, one begins seaching specifically for data supporting the observation of fairies. When data is selected to fit a pre-supposed pattern, other explanatory patterns may be easily overlooked.

I might interject my own argument here for a moment and move my own goal posts intentionally, if I may - I recognise now that the example I used has a large problem. Fairies aren't a model in themselves explaining a flying humanoid; there is no single, straight forward criteria explaining what one means. Indeed, it's probably one of the biggest holes many paranormalists and faithers fall into (definining their model with any precision).

Oh yes, for sure.

I once spent considerable time debating a woman on a "paranormal" list who claimed that she had attained SPIRITUAL POWERS through her acceptance of HIGHER CONSCIOUSNESS (she liked to intersperse her text heavily with all-caps, rather like a religious tract). It took months of constant prodding and wading through mystical obfuscation that would have made a Zen master blush to get her to actually state what any of these alleged "powers" actually enabled her to do.

When she finally did describe one of them (basically remote viewing), I proposed a simple demonstration/test -- at which point she spent another month redifining the alleged power as everything from astral projection to physical teleportation via a "hyperdimension". Basically she invalidated any test I proposed by saying that particular test could only test {fill in 'spiritual power' of your choice}, whereas what she could do was really {fill in different 'spiritual power' of your choice}, etc., etc. yadda, yadda.

The one that always cracks me up is the mystic who says -- usually repeatedly -- that what they are trying to convey can't be presented in words, nevertheless, they then procede to fill hundreds of megabytes of webspace and/or thousands of pages of physical text talking about it.

Again, I'm assuming you have more particle physics experience than I do. Would it not be possible (if unlikely) to see the results of a particle collision and witness, say, two particles where your maths initially only counted for one? Have there never been moments in science history where an unexpected observation with no immediately recognisable relationship to accepted models has resulted in the support of a weaker model?

Oh, certainly. In your first example, if something were empirically observed from a particle collision that wasn't predicted by the mathematical model for that collision -- that is, if it were observed many times -- then the mathematical model would be called into question. In that sort of situation the mathematical model is the hypothesis, or at least a part of it. If observation consistently fails to support the hypothesis, then the hypothesis is either refined or scrapped, as need be.

If that's what you've been saying, I have no disagreement there.

I initially had a different impression of what you were trying to convey, which seemed to be along the lines of just proposing an "explanation" out of whole cloth, and then going out to see if it was supported by evidence.

The difference is that between a physicist observing that things dropped fall to the ground, asking why, proposing a model, and testing it -- and an alchemist deciding that there must be a way to turn lead into gold, and then going off on a quest for the Philosopher's Stone. It's the difference between seeking an explanation for an observation, and seeking an observation to fit an imagined explanation.

This seems somewhat chicken and egg, then. Remember, I'm not qualifying it as good evidence - just defining the observation as 'evidence' or 'not evidence'. If you have no pre-existing evidence at all for a model, then there is going to have to be a first observation which inspires the speculation. Indeed, we both agree it would be far from sufficient to accept the model, but it still must be considered evidence in order for it to accumulate.

If you had no pre-existing evidence at all for a model why would you have the model at all?

I can see the chicken-and-egg potential, but I'm not sure our minds generally work that simplistically. Did people invent demons first and then decide that the Earth had to be flat so there would be a place for the demons to live, over the edge? Or did they decide that the Earth was flat, and something had to exist over the edge, therefore they peopled that place with demons?

The truth is that both demons and the flat Earth were invented to explain other observations, and the two just happened to get slapped together at some point.

Not at all. I remind you I'm not a particle physicist, so could be butchering their craft big time.

I'm not a particle physicist, either, though I did spend some time studying the subject.

I'm picturing a possibly fantasy situation where a particle is smashed, numbers are crunched, particles counted and something comes up amiss, leading in itself to then speculating if an anomalous result is a new phenomena. Of course chances are low, but I would find such a situation (if even possible) where such a speculation is not even considered to be somewhat against how science works.

That kind of speculation goes on all the time. It's speculation about an observed phenomenon: "we expected two gamma rays with energy 'X', but we got two gamma rays with energy 'X-(1x10^-19)' ... I wonder where the missing energy went?"

I'm not in 100% agreement with your view that at the time, there was the sentiment that the existing theory left a great deal of the process unexplained. While particle physics isn't my field, science history is - and it was far from black and white in terms of any acceptance of the necessity for novel explanations. Many at the time felt fermentation was merely a chemical reaction, and the presence of replicating life forms was coincidence. For many, there was no need to ask how it started (you do have to bear in mind that reductionism as we understand it today wasn't a strong driving force behind discoveries in the past. People were satisfied with 'it just is'. Mind you, many of the greatest discoveries were made by vitalists and the like who were happy with such answers).

Well, I partly agree. I didn't say that there "was the sentiment" that the existing theory of fermentation left a great deal of theprocess unexplained -- the fact is that the existing theory did leave a great deal of the process unexplained. It was inevitible that sooner or later some people would notice this fact, and wonder about a more complete explanation.

For that matter, it can be justly said that there wasn't much concern amongst the general populace in 1905 about the photoelectric effect, and even most scientists and engineers were not greatly perturbed by the fact that Newtonian machanics permitted mass to accelerate to infinite velocity. Yet Einstein's papers on the photoelectric effect and special relativity changed the course of science in the century following their publication, and ultimately engendered whole new branches of science.

Einstein happened to be one of those who "noticed" that additional explanation was necessary. Pertinent to our discussion, what he noticed was that existing hypotheses didn't fully explain existing observations in certain areas of exploration, so he proposed new hypotheses.

No, I owe you a big thanks for the criticisms, even if we ultimately agree. While I might be 'right' overall (by populat agreement), I still like to clarify my personal understanding of the details.

I wasn't intending to criticize so much as discuss. I don't by any means claim to have a lockdown on "the Truth" -- I leave that to the obfuscatory mystics.

Athon[/QUOTE]

 

[Ron_Tomkins]

Guys guys, what's this whole fairy talk? Didn't I publicly kill all of the fairies in the other thread already?

 

[athon]

Guys guys, what's this whole fairy talk? Didn't I publicly kill all of the fairies in the other thread already?

We're starting a movement to bring them back.

Dr. H, I'll see if I can find the time later to digest your points. They are good ones, as per usual. And I didn't mean 'criticise' at the end there as a bad thing - quite the opposite, in fact. They've done a good job of making me look closely at my argument.

Athon

 

[Loss Leader]

What is your definition of 'evidence'? Does it only exist in conjunction with what we currently know in the universe? Is seeing a fairy evidence for fairies?

Evidence is anything that tends to make a proposition more or less true.

 

[Dr H]

We're starting a movement to bring them back.

Dr. H, I'll see if I can find the time later to digest your points. They are good ones, as per usual. And I didn't mean 'criticise' at the end there as a bad thing - quite the opposite, in fact. They've done a good job of making me look closely at my argument.

Athon

No worries.

Meanwhile, I'm going to get back to my beer, before the damned fairies start bothering me again.

 

[arthwollipot]

Evidence is anything that tends to make a proposition more or less true.

Excuse me for butting in, but that definition sounds wishy-washy to me. I understand that the phrase is supposed to mean "more true or less true" rather than "more-or-less true", but it seems to me that this definition can encompass just about anything.