From:	I.E_Johansson
Subject:	New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 06:39:59 GMT

Martyn in your message:
in your message
news:gr0tu09o49jn25btpdat9p123ffpup2t0m@4ax.com...
you wrote:
"Because trade wasn't happening, it's therefore an interesting question as
to the source of the substances. I'm happy to accept that it was probably
old world plants used in the mummification process or some similar
explanation, and the true story won't really tell us anything new, but the
question does provide an opportunity to analyse what evidence we can think
up / conclusions we can draw from it."

Here you start out with an already decided conclusion:
"Because trade wasn't happening.."
Which is a shadow statement since the correct situation today isn't that we
can prove or even presume that.
Please remember that an area can only be presumed to be without one single
known 'dot' if it's been completely investigated and shown to be without any
dots what so ever or the areas around the scientific field you analyse have
been proven to be without any dots or hardly any dots AND you have performed
a significant number of random tests to show that it's highly unlikely that
you will find any dot. Proof for such assumption can't be put forward if
these analyses haven't been made.

Thus what you actually do is starting out with an:
Unproven assumption. Lack of knowledge doesn't mean that knowledge can't be
gained!

Now you in the second part of first phrase continues with: "it's therefore
an interesting question as to the source of the substances."
The value of such a 'conclusion' is zero, null. Why? What you done is the
atletic acrobat trick of a saltomotal without checking that there is a
safety roap to hang on to if anything doesn't go your way,
that's one thing,
but what you also done is trying to perform this saltomotal from an unknown
hight without checking how and where you will land in the end.
In other word in the first sentence you placed an unproven assumption using
it for the second half of the sentece as if it was proven and thus possible
to draw a conclusion from.
That isn't so.
Thus your continued sentences falls to the ground because you are using an
example of a circle-proof to prove your case.

Might be that you aren't openminded. But you need to present valid arguments
no matter which case you are discussing. The minimum requirements for an
argument to be valid is that it doesn't start from an unproven assumption
using it as if it was possible to draw a conclusion from that leading up to
the arguments in question. If you do what you done in the quoted phrase you
can't end up with anything but invalid argument/-s.

Is it possible for you to rephrase your statement-lines?

Inger E

From:	george
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	20 Jan 2005 11:33:19 -0800

Doug Weller wrote:
> On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier
wrote:
>
> >
> >Martyn is blatantly ignoring the old dictum "Absence of evidence is
not
> >evidence of absence" and drawing a fallacious conclusion from an
argumentum
> >ex silentio. Consider how little has actually survived from ancient
Egypt, a
> >tiny fraction of all the evidence that may once have existed. It is
wrong to
> >infer from this absence of evidence that, during the several
millennia of
> >Egyptian history, there was no contact at all with other parts of
the world,
> >or indeed the universe.
>
> I've never understood that 'old dictum'.
> Absence of evidence is in fact evidence of absence. Not proof, but
> evidence of the probability of absence. And how likely that is
depends
> upon the context.

If there -was- contact between Egypt and the Americas there would be
evidence of this trade on -both- sides of the Atlantic.
No-one has yet found pollen from plants of Americas origin in the
ancient Egyptian archaeological horizons and every site is 'floated' to
recover and examine plant pollen to determine flora present at that
site at that time.

>
> For instance, if we find a certain type of fossil in a certain type
of
> context on continent A, but we don't find it in a similar context on
> continent B, that suggests pretty strongly that the lack of fossils
means
> a lack of the animal involved.

That is basic common sense Doug :-)
If it ain't there it doesn't leave a trace

From:	dunkers at pacbell.net
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	20 Jan 2005 22:17:57 -0800

I'm happy to accept that it was probably
old world plants used in the mummification process or some similar
explanation, and the true story won't really tell us anything new, but
the
question does provide an opportunity to analyse what evidence we can
think
up / conclusions we can draw from it."

Yes, but it also allows us to be drawn into a ridiculous metaphysical
discussion. To return to the evidence; the tests done were hair folicle
tests which are evidence that the substance in question was ingested by
an alive pharoh, ergo not part of the mummification process or later
contamination.

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 06:51:55 GMT

skrev i meddelandet
news:1106288277.359830.162870@c13g2000cwb.googlegroups.com...
>
>
> I'm happy to accept that it was probably
> old world plants used in the mummification process or some similar
> explanation, and the true story won't really tell us anything new, but
> the
> question does provide an opportunity to analyse what evidence we can
> think
> up / conclusions we can draw from it."
>
> Yes, but it also allows us to be drawn into a ridiculous metaphysical
> discussion. To return to the evidence; the tests done were hair folicle
> tests which are evidence that the substance in question was ingested by
> an alive pharoh, ergo not part of the mummification process or later
> contamination.

That I missed. Would you please explain why alive and not during
mummification process. It's also interesting to see your point that it isn't
later contamination.

I don't agree with you that it's a metaphysical
discussion. This type of discussion is what science is all about, presenting
you with the tools you can use in theory-construction and which you can't.
It's also a discussion about of how your own theoretical approach to the
'things' you observe and how you draw your own conclusion from that. That's
basic and essential.

Inger E
>

From:	David B
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 13:48:42 GMT

I.E_Johansson wrote in message <3nIHd.128108$dP1.459841@newsc.telia.net>...
>
>Martyn in your message:
>news:gr0tu09o49jn25btpdat9p123ffpup2t0m@4ax.com...
>you wrote:
>>"Because trade wasn't happening, it's therefore an interesting question
>> as to the source of the substances. I'm happy to accept that it was
>> probably old world plants used in the mummification process or some
>> similar explanation, and the true story won't really tell us anything
>> new, but the question does provide an opportunity to analyse what
>> evidence we can think up / conclusions we can draw from it."
>
>Is it possible for you to rephrase your statement-lines?

Easy. For Martyn's first four words, substitute:
"As other expected evidence for trade is absent"...

David B.

From:	Alan Crozier
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 15:01:57 GMT

"David B" wrote in message
news:_EOHd.98$l8.82@newsfe2-gui.ntli.net...
> I.E_Johansson wrote in message
<3nIHd.128108$dP1.459841@newsc.telia.net>...
> >
> >Martyn in your message:
> >news:gr0tu09o49jn25btpdat9p123ffpup2t0m@4ax.com...
> >you wrote:
> >>"Because trade wasn't happening, it's therefore an interesting question
> >> as to the source of the substances. I'm happy to accept that it was
> >> probably old world plants used in the mummification process or some
> >> similar explanation, and the true story won't really tell us anything
> >> new, but the question does provide an opportunity to analyse what
> >> evidence we can think up / conclusions we can draw from it."
> >
> >Is it possible for you to rephrase your statement-lines?
>
> Easy. For Martyn's first four words, substitute:
> "As other expected evidence for trade is absent"...

No, David,

Martyn is blatantly ignoring the old dictum "Absence of evidence is not
evidence of absence" and drawing a fallacious conclusion from an argumentum
ex silentio. Consider how little has actually survived from ancient Egypt, a
tiny fraction of all the evidence that may once have existed. It is wrong to
infer from this absence of evidence that, during the several millennia of
Egyptian history, there was no contact at all with other parts of the world,
or indeed the universe.

Just because there is no firm evidence of extraterrestial visitors, it does
not mean that Erich von Däniken and others are wrong when they explore the
possibility that aliens from advanced civilizations helped the primitive
Egyptians to build the pyramids. You should keep an open mind on this and
reread Chariots of the Gods.

Alan

--
Alan Crozier
Lund
Sweden

From:	Tedd Jacobs
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 09:19:22 -0700

"Alan Crozier" wrote...
> "David B" wrote in message
> news:_EOHd.98$l8.82@newsfe2-gui.ntli.net...
>> I.E_Johansson wrote in message
> <3nIHd.128108$dP1.459841@newsc.telia.net>...
>> >
>> >Martyn in your message:
>> >news:gr0tu09o49jn25btpdat9p123ffpup2t0m@4ax.com...
>> >you wrote:
>> >>"Because trade wasn't happening, it's therefore an interesting question
>> >> as to the source of the substances. I'm happy to accept that it was
>> >> probably old world plants used in the mummification process or some
>> >> similar explanation, and the true story won't really tell us anything
>> >> new, but the question does provide an opportunity to analyse what
>> >> evidence we can think up / conclusions we can draw from it."
>> >
>> >Is it possible for you to rephrase your statement-lines?
>>
>> Easy. For Martyn's first four words, substitute:
>> "As other expected evidence for trade is absent"...
>
> No, David,
>
> Martyn is blatantly ignoring the old dictum "Absence of evidence is not
> evidence of absence" and drawing a fallacious conclusion from an
> argumentum
> ex silentio. Consider how little has actually survived from ancient Egypt,
> a
> tiny fraction of all the evidence that may once have existed. It is wrong
> to
> infer from this absence of evidence that, during the several millennia of
> Egyptian history, there was no contact at all with other parts of the
> world,
> or indeed the universe.
>
> Just because there is no firm evidence of extraterrestial visitors, it
> does
> not mean that Erich von Däniken and others are wrong when they explore the
> possibility that aliens from advanced civilizations helped the primitive
> Egyptians to build the pyramids. You should keep an open mind on this and
> reread Chariots of the Gods.

pass that pipe this way.

From:	Philip Deitiker
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	20 Jan 2005 16:01:34 GMT

In sci.archaeology, Alan Crozier created a message
ID news:FJPHd.14808$d5.123535@newsb.telia.net:
> No, David,
>
> Martyn is blatantly ignoring the old dictum "Absence of
> evidence is not evidence of absence" and drawing a
> fallacious conclusion from an argumentum ex silentio.
> Consider how little has actually survived from ancient
> Egypt, a tiny fraction of all the evidence that may once
> have existed. It is wrong to infer from this absence of
> evidence that, during the several millennia of Egyptian
> history, there was no contact at all with other parts of
> the world, or indeed the universe.
>
> Just because there is no firm evidence of extraterrestial
> visitors, it does not mean that Erich von Däniken and
> others are wrong when they explore the possibility that
> aliens from advanced civilizations helped the primitive
> Egyptians to build the pyramids. You should keep an open
> mind on this and reread Chariots of the Gods.

I prefer the hollow earth theory, it explains what happened
to all those green pygmies dancing around the magnetic north
pole.

Also explains the dissappearance of the roman civilization at
the south pole. Can you imagine what's going to happened when
the Ice dome over the opening collapses!!!?

From:	Doug Weller
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 16:59:22 +0000

On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier wrote:

>
>Martyn is blatantly ignoring the old dictum "Absence of evidence is not
>evidence of absence" and drawing a fallacious conclusion from an argumentum
>ex silentio. Consider how little has actually survived from ancient Egypt, a
>tiny fraction of all the evidence that may once have existed. It is wrong to
>infer from this absence of evidence that, during the several millennia of
>Egyptian history, there was no contact at all with other parts of the world,
>or indeed the universe.

I've never understood that 'old dictum'.
Absence of evidence is in fact evidence of absence. Not proof, but
evidence of the probability of absence. And how likely that is depends
upon the context.

For instance, if we find a certain type of fossil in a certain type of
context on continent A, but we don't find it in a similar context on
continent B, that suggests pretty strongly that the lack of fossils means
a lack of the animal involved.

[SNIP]

Doug
--
Doug Weller -- exorcise the demon to reply
Doug & Helen's Dogs http://www.dougandhelen.com
A Director and Moderator of The Hall of Ma'at http://www.hallofmaat.com
Doug's Archaeology Site: http://www.ramtops.co.uk

From:	Alan Crozier
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 18:17:10 GMT

"Doug Weller" wrote in message
news:dgovu0tevvdikh1rcm4pgqv3s8frji7hnc@4ax.com...
> On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier wrote:
>
> >
> >Martyn is blatantly ignoring the old dictum "Absence of evidence is not
> >evidence of absence" and drawing a fallacious conclusion from an
argumentum
> >ex silentio. Consider how little has actually survived from ancient
Egypt, a
> >tiny fraction of all the evidence that may once have existed. It is wrong
to
> >infer from this absence of evidence that, during the several millennia of
> >Egyptian history, there was no contact at all with other parts of the
world,
> >or indeed the universe.
>
> I've never understood that 'old dictum'.
> Absence of evidence is in fact evidence of absence. Not proof, but
> evidence of the probability of absence. And how likely that is depends
> upon the context.
>
> For instance, if we find a certain type of fossil in a certain type of
> context on continent A, but we don't find it in a similar context on
> continent B, that suggests pretty strongly that the lack of fossils means
> a lack of the animal involved.

Yes, Doug. In fact, the dictum should really be "Absence of evidence may not
be _proof_ of absence, but it can be _evidence_." It only works in a
language that makes a clear dictinction between evidence and proof.

Actually, I first found that qualification of the old dictum in something
written by David Rohl. (Yes, I admit it, I have read Rohl with an open mind,
but I didn't
inhale.)

I even made the qualified version of the dictum the basis for a conference
paper about the meaning of the name Vinland. You've all read Vinland
Revisited, I trust. It's on page 332.

Alan

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 19:27:15 GMT

"Alan Crozier" skrev i meddelandet
news:GASHd.14821$d5.123764@newsb.telia.net...
> "Doug Weller" wrote in message
> news:dgovu0tevvdikh1rcm4pgqv3s8frji7hnc@4ax.com...
> > On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier
wrote:
> >
> > >
> > >Martyn is blatantly ignoring the old dictum "Absence of evidence is not
> > >evidence of absence" and drawing a fallacious conclusion from an
> argumentum
> > >ex silentio. Consider how little has actually survived from ancient
> Egypt, a
> > >tiny fraction of all the evidence that may once have existed. It is
wrong
> to
> > >infer from this absence of evidence that, during the several millennia
of
> > >Egyptian history, there was no contact at all with other parts of the
> world,
> > >or indeed the universe.
> >
> > I've never understood that 'old dictum'.
> > Absence of evidence is in fact evidence of absence. Not proof, but
> > evidence of the probability of absence. And how likely that is depends
> > upon the context.
> >
> > For instance, if we find a certain type of fossil in a certain type of
> > context on continent A, but we don't find it in a similar context on
> > continent B, that suggests pretty strongly that the lack of fossils
means
> > a lack of the animal involved.
>
> Yes, Doug. In fact, the dictum should really be "Absence of evidence may
not
> be _proof_ of absence, but it can be _evidence_." It only works in a
> language that makes a clear dictinction between evidence and proof.
>
> Actually, I first found that qualification of the old dictum in something
> written by David Rohl. (Yes, I admit it, I have read Rohl with an open
mind,
> but I didn't
> inhale.)
>
> I even made the qualified version of the dictum the basis for a conference
> paper about the meaning of the name Vinland. You've all read Vinland
> Revisited, I trust. It's on page 332.
>
> Alan

Alan,
you got it wrong this time. Absence of evidence NEVER EVER can be evidence
of absence!
That it can be is an indication for absence is an other thing. But never
ever evidence!!! That's elementary knowledge.

You might not have had Method courses like this one from an English
University:
http://dolphin.mcs.st-and.ac.uk/~charles/ID2003.htm

or from any Swedish University's Method courses,
never the less this is basic knowledge! Can't understand that you don't know
that.

Inger E

>
>
>
>

From:	Alan Crozier
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 20:29:33 GMT

"I.E_Johansson" wrote in message
news:nCTHd.14825$d5.123843@newsb.telia.net...
>
> "Alan Crozier" skrev i meddelandet
> news:GASHd.14821$d5.123764@newsb.telia.net...
> > "Doug Weller" wrote in message
> > news:dgovu0tevvdikh1rcm4pgqv3s8frji7hnc@4ax.com...
> > > I've never understood that 'old dictum'.
> > > Absence of evidence is in fact evidence of absence. Not proof, but
> > > evidence of the probability of absence. And how likely that is
depends
> > > upon the context.
> > >
> > > For instance, if we find a certain type of fossil in a certain type of
> > > context on continent A, but we don't find it in a similar context on
> > > continent B, that suggests pretty strongly that the lack of fossils
> means
> > > a lack of the animal involved.
> >
> > Yes, Doug. In fact, the dictum should really be "Absence of evidence may
> not
> > be _proof_ of absence, but it can be _evidence_." It only works in a
> > language that makes a clear dictinction between evidence and proof.
> >
>
> Alan,
> you got it wrong this time. Absence of evidence NEVER EVER can be evidence
> of absence!
> That it can be is an indication for absence is an other thing. But never
> ever evidence!!! That's elementary knowledge.
>
> You might not have had Method courses like this one from an English
> University:
> http://dolphin.mcs.st-and.ac.uk/~charles/ID2003.htm
>
> or from any Swedish University's Method courses,
> never the less this is basic knowledge! Can't understand that you don't
know
> that.

Evidence is not proof, just indications of varying strength. That is the
meaning of the word in English. That is why there is often _evidence_ both
for and against a proposition. There is never _proof_ both for and against
something. When something has not yet been proved in one way or another,
different evidence is used by both sides in the argument.

If you don't believe me, I quote the definition of evidence from the Concise
Oxford Dictionary:

the available facts, circumstances, etc. supporting or otherwise a belief,
proposition, etc., or indicating whether or not a thing is true or valid.

Note the words "supporting" and "indicating". No mention of "proving".

You can't think in Swedish on this one, as the Swedish word _bevis_ is
ambiguous, meaning both proof and evidence. I *did* warn you that the
qualified axiom "only works in a language that makes a clear dictinction
between evidence and proof".

So, I insist that "Absence of evidence may not be _proof_ of absence, but it
can be _evidence_." I don't think course ID2003 - Science Methods would
disagree with me on that one. Or what do you think they teach students in
answer to the question "what does absence of evidence mean?"

Remember, this is the use of words in English we are discussing. Keep an
open mind.

Alan

--
Alan Crozier
Lund
Sweden

From:	Doug Weller
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 22:41:15 +0000

On Thu, 20 Jan 2005 20:29:33 GMT, in sci.archaeology, Alan Crozier wrote:

>"I.E_Johansson" wrote in message
>news:nCTHd.14825$d5.123843@newsb.telia.net...
>>
>> "Alan Crozier" skrev i meddelandet
>> news:GASHd.14821$d5.123764@newsb.telia.net...
>> > "Doug Weller" wrote in message
>> > news:dgovu0tevvdikh1rcm4pgqv3s8frji7hnc@4ax.com...
>> > > I've never understood that 'old dictum'.
>> > > Absence of evidence is in fact evidence of absence. Not proof, but
>> > > evidence of the probability of absence. And how likely that is
>depends
>> > > upon the context.
>> > >
>> > > For instance, if we find a certain type of fossil in a certain type of
>> > > context on continent A, but we don't find it in a similar context on
>> > > continent B, that suggests pretty strongly that the lack of fossils
>> means
>> > > a lack of the animal involved.
>> >
>> > Yes, Doug. In fact, the dictum should really be "Absence of evidence may
>> not
>> > be _proof_ of absence, but it can be _evidence_." It only works in a
>> > language that makes a clear dictinction between evidence and proof.
>> >
>>
>> Alan,
>> you got it wrong this time. Absence of evidence NEVER EVER can be evidence
>> of absence!
>> That it can be is an indication for absence is an other thing. But never
>> ever evidence!!! That's elementary knowledge.
>>
>> You might not have had Method courses like this one from an English
>> University:
>> http://dolphin.mcs.st-and.ac.uk/~charles/ID2003.htm
>>
>> or from any Swedish University's Method courses,
>> never the less this is basic knowledge! Can't understand that you don't
>know
>> that.
>
>Evidence is not proof, just indications of varying strength. That is the
>meaning of the word in English. That is why there is often _evidence_ both
>for and against a proposition. There is never _proof_ both for and against
>something. When something has not yet been proved in one way or another,
>different evidence is used by both sides in the argument.
>
>If you don't believe me, I quote the definition of evidence from the Concise
>Oxford Dictionary:
>
>the available facts, circumstances, etc. supporting or otherwise a belief,
>proposition, etc., or indicating whether or not a thing is true or valid.
>
>Note the words "supporting" and "indicating". No mention of "proving".
>
>You can't think in Swedish on this one, as the Swedish word _bevis_ is
>ambiguous, meaning both proof and evidence. I *did* warn you that the
>qualified axiom "only works in a language that makes a clear dictinction
>between evidence and proof".
>
Ah, I'm glad I didn't respond to what Inger had written, which was, in
English, simply wrong.

>So, I insist that "Absence of evidence may not be _proof_ of absence, but it
>can be _evidence_." I don't think course ID2003 - Science Methods would
>disagree with me on that one. Or what do you think they teach students in
>answer to the question "what does absence of evidence mean?"
>
>Remember, this is the use of words in English we are discussing. Keep an
>open mind.
>
Thanks.

Doug

--
Doug Weller -- exorcise the demon to reply
Doug & Helen's Dogs http://www.dougandhelen.com
A Director and Moderator of The Hall of Ma'at http://www.hallofmaat.com
Doug's Archaeology Site: http://www.ramtops.co.uk

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 23:39:47 GMT

Alan,
what you wrote in your former post isn't exactly what you expressed in the
latest one. With the later I can agree with the former as the sentences were
I can't.
OK Thanks for clearing it out that an absence of evidence can't be treated
as an evidence of absence. That's important. That it can be used as an
indicator one or both ways is a totally different thing.

Inger E

From:	Alan Crozier
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 07:27:18 GMT

"I.E_Johansson" wrote in message
news:7jXHd.14853$d5.124050@newsb.telia.net...
> Alan,
> what you wrote in your former post isn't exactly what you expressed in the
> latest one. With the later I can agree with the former as the sentences
were
> I can't.
> OK Thanks for clearing it out that an absence of evidence can't be treated
> as an evidence of absence. That's important. That it can be used as an
> indicator one or both ways is a totally different thing.

But indications *can* also be used as evidence. Remember that the Swedish
legal term "indiciebevis" is called "circumstantial evidence" in English. In
other words, it is evidence of a kind, although not proof.

So it is not a "totally different thing" in English. In other words, when
you say that "absence of evidence can be used as an indicator", you are in
effect saying that "absence of evidence can be evidence of absence".

Once again, in English, evidence is not proof. It can be used to argue a
proposition, it may help to establish proof. When you see the English word
"evidence" don't think Swedish "bevis", think "belägg, stöd, vittnesbörd,
tecken, spår, indicier" and all the other relevant words in my
English-Swedish dictionary.

Alan

--
Alan Crozier
Lund
Sweden

From:	Doug Weller
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 05:59:52 +0000

On Thu, 20 Jan 2005 23:39:47 GMT, in sci.archaeology, I.E_Johansson wrote:

>Alan,
>what you wrote in your former post isn't exactly what you expressed in the
>latest one. With the later I can agree with the former as the sentences were
>I can't.
>OK Thanks for clearing it out that an absence of evidence can't be treated
>as an evidence of absence. That's important. That it can be used as an
>indicator one or both ways is a totally different thing.

Not in English it isn't. Oxford Dictionary of English (the big single
volume one):
"the available body of facts or information indicating whether a belief or
proposition is true or valid"
That's the first meaning given, the 3rd is "signs or indications of
something"

Absence of evidence is evidence (indication) of absence. That's what it
means in English. As Alan says, you've misunderstood the English meaning
of the word.

Doug
--
Doug Weller -- exorcise the demon to reply
Doug & Helen's Dogs http://www.dougandhelen.com
A Director and Moderator of The Hall of Ma'at http://www.hallofmaat.com
Doug's Archaeology Site: http://www.ramtops.co.uk

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 06:47:27 GMT

Doug,
You can't use a dictionary to tell you what the Old Greeks knew and what
every serious scholar has to have learnt. You see:
Absence of evidence isn't the same as evidence of absence!
That has nothing what so ever to do with this or that language's
dictionaries. This is basic knowledge for every single scholar. It's one of
the first things you learn reading philosophy and one of the first facts you
have to go thru showing yourself to have understand when studying Methods of
Science. No matter which subject no matter where and when.

If you can't understand this, then it's easy to understand why you haven't
been able to present valid arguments in many of the questions discussed
here.

There are a lot of theories/thesis and facts which can't be proven true. But
many of those can be falsified since it only takes one single example of the
kind which the theory/thesis or 'fact' say isn't true. Following is taking
this to next level.

You can only ask the questions you know might be asked to any kind of given
strata, observation, documentation and or artifacts found. That's simple.
But how can you be sure that what you observe is what's really there? You
can't. Let's take the old traditional chair from the classes of Philosophy.
The tutor/teacher puts a chair in front of you and ask: what's this? you
rise your hand and answer: a chair. The tutor/teacher asks: How do you know?
You continue I know that. The tutor/teacher continue Why and how can you
prove it? You say 'If I can sit in it and it's not a sofa and not an
armchair, then it's a chair. The tutor/teacher continue: That's not a proof
of what it is, it's only a proof that you have used things alike as a chair.
In other word you are using your own, but limited, experience.
How can you be sure that your experience is the only way to interpret what
you see? You can't. You can only relate to what you have learnt either
oraly, from written words or your own experience. That's nothing that say
that you are correct.
How can you even be sure that what you see exists?
and so on. I do hope you have had the pleasure of having a good
philosoph-teacher. Every scholar there is ought to have had one. If you
aren't aware of the basic factors to form a valid argument in a discussion,
it's then you try to pick on details which aren't important at all to the
discussion.

In other word as often been the case from several here who written Ad
Hominem or personal attacks or used namecalling. It's a typical phenomena of
those who can't form an argument or a contra-argument trying to dismiss a
question either by picking on unimportant details, trying to lean to
circle-proofs and or stalking to stop valid arguments from being discussed.

In the specific case we are discussing, that absence of evidence never ever
can be an evidence of absence, you are trying to change subject to what you
from your experience can find from texts in English dictionary's and
encyclopedia. The world has seen many languages, but that doesn't matter
when it comes to what's in this or that work and or book. You can't know
anything what so ever about what's in an unexcavated area 5 meters from your
own house, it's even more limited chances for you to know what's in an
unexcatvated field you never seen yourself.

You may believe that while field A and field C hasn't shown any artifacts of
X-type then it's unlikely that field B in between the others can have one.
Believing isn't knowing.

As my teacher used to say in discussion like this: Believe you can do in the
church, when it comes to science you either know for sure or you don't. If
you haven't tested or searched you definitely can't say you know. No matter
what.
Thus you can't use the argument that absence of evidence can be used to
prove anything but that you haven't been able to form question or to do
deeper studies to form a valid evidence. All you have done is shown that you
don't know theories of science by heart.

Inger E

From:	Alan Crozier
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 07:27:18 GMT

"I.E_Johansson" wrote in message
news:3A1Id.128188$dP1.460104@newsc.telia.net...
> Doug,
> You can't use a dictionary to tell you what the Old Greeks knew and what
> every serious scholar has to have learnt. You see:
> Absence of evidence isn't the same as evidence of absence!

I agree. It's not the same. But absence of evidence can be cited as evidence
of absence. Don't think of evidence as proof. By the way, what is the
ancient Greek wording of this scientific

> That has nothing what so ever to do with this or that language's
> dictionaries. This is basic knowledge for every single scholar. It's one
of
> the first things you learn reading philosophy and one of the first facts
you
> have to go thru showing yourself to have understand when studying Methods
of
> Science. No matter which subject no matter where and when.
>
> If you can't understand this, then it's easy to understand why you haven't
> been able to present valid arguments in many of the questions discussed
> here.

Ad hominem

> There are a lot of theories/thesis and facts which can't be proven true.
But
> many of those can be falsified since it only takes one single example of
the
> kind which the theory/thesis or 'fact' say isn't true. Following is taking
> this to next level.
>

>
> As my teacher used to say in discussion like this: Believe you can do in
the
> church, when it comes to science you either know for sure or you don't. If
> you haven't tested or searched you definitely can't say you know. No
matter
> what.

If you insist on saying the opposite, that "absence of evidence can't be
treated as evidence of absence", then you have to admit the possibility that
extraterrestrials helped the ancient Egyptians to build the pyramids, and
you have to keep an open mind about all kinds of impossibilities. You
definitely can't say that you know either way. But not even you, I guess,
are open to the possibility of every unlikely thing for which there is
evidence of absence. Read the article that Steve Marcus provided a link to.

> Thus you can't use the argument that absence of evidence can be used to
> prove anything but that you haven't been able to form question or to do
> deeper studies to form a valid evidence. All you have done is shown that
you
> don't know theories of science by heart.

Ad hominem

Alan

--
Alan Crozier
Lund
Sweden

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 07:52:27 GMT

"Alan Crozier" skrev i meddelandet
news:q92Id.14874$d5.124329@newsb.telia.net...
> "I.E_Johansson" wrote in message
> news:3A1Id.128188$dP1.460104@newsc.telia.net...
> > Doug,
> > You can't use a dictionary to tell you what the Old Greeks knew and what
> > every serious scholar has to have learnt. You see:
> > Absence of evidence isn't the same as evidence of absence!
>
> I agree. It's not the same. But absence of evidence can be cited as
evidence
> of absence. Don't think of evidence as proof. By the way, what is the
> ancient Greek wording of this scientific

Here you are wrong which I tried to explain before. It has nothing to do if
or if not you think of evidence as proof. It has to do with the simple fact
which we can call an Axiom of Science: never ever can an absence of anything
be used as a proof of absence as long as you haven't done a complete 100%
investigation, study etc! This is basic Alan. Thought you knew that. You
can't even use it to cite. Never ever if you want to use scholarly
methodology. What you can use it as is an indicator, indication that this or
that is more likely. But if you don't include the 'more likely' then your
argumentation falls down and becomes invalid.

I found one link to Aristoteles of all, but it was in Greek and I am sad to
say I never studied Greek. Then I found some ref litterature for me
obscure=not known language which looked like it had kyrillic letters..... I
am not in Linköping where I have several friends who knows those languages
by heart....
>
> > That has nothing what so ever to do with this or that language's
> > dictionaries. This is basic knowledge for every single scholar. It's one
> of
> > the first things you learn reading philosophy and one of the first facts
> you
> > have to go thru showing yourself to have understand when studying
Methods
> of
> > Science. No matter which subject no matter where and when.
> >
> > If you can't understand this, then it's easy to understand why you
haven't
> > been able to present valid arguments in many of the questions discussed
> > here.
>
> Ad hominem

No not since it's stage B in an A, B, C, D and E presentation of the factors
and why. That's the normal way to describe and explain this for students!

Inger E

From:	Alan Crozier
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 11:09:33 GMT

"I.E_Johansson" wrote in message
news:%w2Id.128190$dP1.460020@newsc.telia.net...
> Here you are wrong which I tried to explain before. It has nothing to do
if
> or if not you think of evidence as proof. It has to do with the simple
fact
> which we can call an Axiom of Science: never ever can an absence of
anything
> be used as a proof of absence as long as you haven't done a complete 100%
> investigation, study etc! This is basic Alan. Thought you knew that.

Let me point out where you went wrong here, Inger. We were talking about
evidence. In the paragraph above you change the subject to proof (which is
something very different) by saying "never ever can an absence of anything
be used as a proof of absence".

To simplify what has happened in the debate:

Alan says X

Inger says, No, Alan you are wrong to say Y.

It is true that Alan would be wrong to say Y, but Alan said X, not Y. By
changing X to Y, Inger has set up a strawman, which is not the best way to
make progress in a debate. Nor is it nice to cast aspersions on the
education of the other people in the debate.

Alan

--
Alan Crozier
Lund
Sweden

From:	Alan Crozier
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 08:06:37 GMT

"Alan Crozier" wrote in message
news:q92Id.14874$d5.124329@newsb.telia.net...

and here I am again, correccting myself because I left out a word (which led
me to explain myself more clearly):

> "I.E_Johansson" wrote in message
> news:3A1Id.128188$dP1.460104@newsc.telia.net...
> > Doug,
> > You can't use a dictionary to tell you what the Old Greeks knew and what
> > every serious scholar has to have learnt. You see:
> > Absence of evidence isn't the same as evidence of absence!
>
> I agree. It's not the same. But absence of evidence can be cited as
evidence
> of absence. Don't think of evidence as proof. By the way, what is the
> ancient Greek wording of this scientific

I meant: What is the ancient Greek wording of this scientific dictum?

Let me put it another way which might be easier. In Swedish I think it is
worded as follows:

Avsaknaden av bevis är inte bevis för avsaknaden.

And that can be translated:

Absence of proof is not proof of absence.

Nobody (not even Doug or I) would think of deleting the "not" to change that
to:

Absence of proof is proof of absence.

However, the English version we have been using here doesn't have the word
"proof", but "evidence". The two words are not synonymous, as I have pointed
out. So we are talking about a very different dictum. In "Absence of
evidence is not evidence of absence" you can in fact delete the "not" and
say that "Absence of evidence can be evidence (albeit not proof) of
absence". To translate that back into my imperfect Swedish:

Avsaknaden av tecken/spår/indicier/vittnesbörd kan användas som
tecken/spår/indicier/vittnesbörd (om än inte bevis) på avsaknaden

which is close to what you yourself said, that "absence of evidence ... can
be used as an indicator".

Alan

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 10:50:50 GMT

"Alan Crozier" skrev i meddelandet
news:hK2Id.14877$d5.124298@newsb.telia.net...
> "Alan Crozier" wrote in message
> news:q92Id.14874$d5.124329@newsb.telia.net...
>
> and here I am again, correccting myself because I left out a word (which
led
> me to explain myself more clearly):
>
> > "I.E_Johansson" wrote in message
> > news:3A1Id.128188$dP1.460104@newsc.telia.net...
> > > Doug,
> > > You can't use a dictionary to tell you what the Old Greeks knew and
what
> > > every serious scholar has to have learnt. You see:
> > > Absence of evidence isn't the same as evidence of absence!
> >
> > I agree. It's not the same. But absence of evidence can be cited as
> evidence
> > of absence. Don't think of evidence as proof. By the way, what is the
> > ancient Greek wording of this scientific
>
> I meant: What is the ancient Greek wording of this scientific dictum?

That was what I tried to explain that I neither can copy nor read the Greek
Letters. The only translation I found was to a language with other letters I
can't copy, write or read. Sorry but there are limitations in my
wordprogram.

Inger E

From:	Odysseus
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in
Date:	Sun, 23 Jan 2005 01:59:31 GMT

"I.E_Johansson" wrote:
>
> "Alan Crozier" skrev i meddelandet
> news:hK2Id.14877$d5.124298@newsb.telia.net...

> >
> > I meant: What is the ancient Greek wording of this scientific dictum?
>
> That was what I tried to explain that I neither can copy nor read the Greek
> Letters. The only translation I found was to a language with other letters I
> can't copy, write or read. Sorry but there are limitations in my
> wordprogram.
>
If you would post the original link here I could certainly
transliterate what the page says, and maybe even translate it.

--
Odysseus

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Sun, 23 Jan 2005 05:38:26 GMT

"Odysseus" skrev i meddelandet
news:41F30527.685121B7@yahoo-dot.ca...
> "I.E_Johansson" wrote:
> >
> > "Alan Crozier" skrev i meddelandet
> > news:hK2Id.14877$d5.124298@newsb.telia.net...
>
>
> > >
> > > I meant: What is the ancient Greek wording of this scientific dictum?
> >
> > That was what I tried to explain that I neither can copy nor read the
Greek
> > Letters. The only translation I found was to a language with other
letters I
> > can't copy, write or read. Sorry but there are limitations in my
> > wordprogram.
> >
> If you would post the original link here I could certainly
> transliterate what the page says, and maybe even translate it.

Odysseus,
forgot you were around. Sorry.
I might have time looking it up next week. Didn't save it in my computer and
now I am following the Verendry track. That takes time and a lot of reading.
However it has proven to pay off reading French, English and Swedish
documents so I guess I stick to that at least till I have read what I now
know to be accessable. There might be a subjectline re. this but not the
next months. Validation and checking you know.

Inger E
>
> --
> Odysseus

From:	Alaca
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 10:53:02 +0100

I.E_Johansson wrote in news:3A1Id.128188$dP1.460104@newsc.telia.net,
[...]

Intermezzo
Inger, there is overwhelming _evidence_ that you are not able to argue
without personal attack. But is that _proof_ you can't?
We can adopt the hypothesis that you can if you want, but according to
professor Adler, "for hypotheses, the main source is evidence".

--
-- Peter Alaca --

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 10:52:52 GMT

Alaca,
If you try to deny me of my rights to defend myself and calling that
defending for personal attacks, then I pity you. You are what you are
P.Alaca@WannaBee. Needn't say it since you chosen the words yourself.

Inger E

"Alaca" skrev i meddelandet
news:41f0d1c7$0$41554$1b2cd167@news.wanadoo.nl...
> I.E_Johansson wrote in news:3A1Id.128188$dP1.460104@newsc.telia.net,
> [...]
>
> Intermezzo
> Inger, there is overwhelming _evidence_ that you are not able to argue
> without personal attack. But is that _proof_ you can't?
> We can adopt the hypothesis that you can if you want, but according to
> professor Adler, "for hypotheses, the main source is evidence".
>
> --
> -- Peter Alaca --

From:	Alaca
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 13:58:58 +0100

I.E_Johansson wrote in news:8a5Id.14890$d5.124212@newsb.telia.net,

>
> "Alaca" skrev i meddelandet
> news:41f0d1c7$0$41554$1b2cd167@news.wanadoo.nl...
>> I.E_Johansson wrote in news:3A1Id.128188$dP1.460104@newsc.telia.net,
>> [...]
>>
>> Intermezzo
>> Inger, there is overwhelming _evidence_ that you are not able to
>> argue without personal attack. But is that _proof_ you can't?
>> We can adopt the hypothesis that you can if you want, but according
>> to professor Adler, "for hypotheses, the main source is evidence".

> Alaca,
> If you try to deny me of my rights to defend myself and calling that
> defending for personal attacks, then I pity you. You are what you are
> P.Alaca@WannaBee. Needn't say it since you chosen the words yourself.

What a strange way to say you agree with me!

--
-- Peter Alaca --
(WannaB_ee_ )

From:	Billy Bob
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine
Date:	Fri, 21 Jan 2005 06:44:09 -0500

Inger......

You must start learning English better... You attack what someone
says...with such "Vile" (and please look up "vile" in an English
dictionary). It makes it appear that you have a real inferiority
complex...and don't tell me I'm wrong... because a number of people I
have discussed this with all agree (and they aren't just people off the
street). And I don't care if you've taught English, or not...You need
to do you Homework. You misunderstand the meanings of MANY words...and
then you tell someone how they would never pass some exam..and so and
so...and all along it's because YOU do not know the correct meaning, or
misrepresent it.
And by he way... this is not a personal attack... I am trying to
help...because your problems with English make you look bad... or
worse.... billy bob

From:	I.E_Johansson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine...
Date:	Fri, 21 Jan 2005 12:09:28 GMT

Billy Bob,
You must stop complaining and also start learning more about dyslexia. I
have no problem what so ever with the spoken or read English language thank
you. On the contrary actually no matter what you believe. Many
non-British-Englishmen makes more mistakes than I ever will. Even if you had
been correct it's not fair to pick on a person you know have
spellingproblems when writing. You know absolutely nothing about my
English-skill nor which courses I have passed so stop complaining. You
better learn that a dyslextic person can be very very good in the language
talking it and reading it and comprehending it. Stop your personal attack on
me. If you don't like my English, keep it to yourself. If you can't follow
my thoughts, well that say more about your skill than it does about my usage
of the English language!

Inger E

"Billy Bob" skrev i meddelandet
news:15141-41F0EB09-106@storefull-3172.bay.webtv.net...
> Inger......
>
> You must start learning English better... You attack what someone
> says...with such "Vile" (and please look up "vile" in an English
> dictionary). It makes it appear that you have a real inferiority
> complex...and don't tell me I'm wrong... because a number of people I
> have discussed this with all agree (and they aren't just people off the
> street). And I don't care if you've taught English, or not...You need
> to do you Homework. You misunderstand the meanings of MANY words...and
> then you tell someone how they would never pass some exam..and so and
> so...and all along it's because YOU do not know the correct meaning, or
> misrepresent it.
> And by he way... this is not a personal attack... I am trying to
> help...because your problems with English make you look bad... or
> worse.... billy bob
>

From:	Joe Jefferson
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in
Date:	Fri, 21 Jan 2005 19:26:45 GMT

Doug Weller wrote:
>
> Absence of evidence is evidence (indication) of absence.

This is true if and only if the evidence is actually absent. It does not
apply if one has never looked for evidence, or if one does not possess
the ability to find the evidence if it does exist. For example, I can
take the fact that no plastic bottle were found in King Tut's tomb as
evidence that none were buried with him. I could not, however, take the
fact that no microbes have ever been observed on Callisto as evidence
that there aren't any living there, because nobody has ever looked at
Callisto with instruments sensitive enough to detect microbes.

--
Joe of Castle Jefferson
http://www.mindspring.com/~jjstrshp
Site Updated November 25th, 2001

"Defend the cause of the weak and fatherless; maintain the rights of the
poor and oppressed. Rescue the weak and needy; deliver them from the
hand of the wicked." - Psalm 82:3-4

From:	Doug Weller
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 21:15:41 +0000

On Fri, 21 Jan 2005 19:26:45 GMT, in sci.archaeology, Joe Jefferson wrote:

>Doug Weller wrote:
>>
>> Absence of evidence is evidence (indication) of absence.
>
>This is true if and only if the evidence is actually absent.

Yes of course. That is what it means.

[SNIP]
--
Doug Weller -- exorcise the demon to reply
Doug & Helen's Dogs http://www.dougandhelen.com
A Director and Moderator of The Hall of Ma'at http://www.hallofmaat.com
Doug's Archaeology Site: http://www.ramtops.co.uk

From:	Doug Weller
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 22:46:23 +0000

On Thu, 20 Jan 2005 18:17:10 GMT, in sci.archaeology, Alan Crozier wrote:

>"Doug Weller" wrote in message
>news:dgovu0tevvdikh1rcm4pgqv3s8frji7hnc@4ax.com...
>> On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier wrote:
>>
>> >
>> >Martyn is blatantly ignoring the old dictum "Absence of evidence is not
>> >evidence of absence" and drawing a fallacious conclusion from an
>argumentum
>> >ex silentio. Consider how little has actually survived from ancient
>Egypt, a
>> >tiny fraction of all the evidence that may once have existed. It is wrong
>to
>> >infer from this absence of evidence that, during the several millennia of
>> >Egyptian history, there was no contact at all with other parts of the
>world,
>> >or indeed the universe.
>>
>> I've never understood that 'old dictum'.
>> Absence of evidence is in fact evidence of absence. Not proof, but
>> evidence of the probability of absence. And how likely that is depends
>> upon the context.
>>
>> For instance, if we find a certain type of fossil in a certain type of
>> context on continent A, but we don't find it in a similar context on
>> continent B, that suggests pretty strongly that the lack of fossils means
>> a lack of the animal involved.
>
>Yes, Doug. In fact, the dictum should really be "Absence of evidence may not
>be _proof_ of absence, but it can be _evidence_." It only works in a
>language that makes a clear dictinction between evidence and proof.
>
Indeed.

>Actually, I first found that qualification of the old dictum in something
>written by David Rohl. (Yes, I admit it, I have read Rohl with an open mind,
>but I didn't
>inhale.)

Yes, he wrote ""The phrase ‘absence of evidence is not evidence of
absence’ is just another way of saying ‘anything goes’ in our
interpretation of the available archaeological evidence"

>I even made the qualified version of the dictum the basis for a conference
>paper about the meaning of the name Vinland. You've all read Vinland
>Revisited, I trust. It's on page 332.
>
Nope, I haven't. Someday.

Doug
--
Doug Weller -- exorcise the demon to reply
Doug & Helen's Dogs http://www.dougandhelen.com
A Director and Moderator of The Hall of Ma'at http://www.hallofmaat.com
Doug's Archaeology Site: http://www.ramtops.co.uk

From:	Eric Stevens
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Fri, 21 Jan 2005 10:09:50 +1300

On Thu, 20 Jan 2005 16:59:22 +0000, Doug Weller
wrote:

>On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier wrote:
>
>>
>>Martyn is blatantly ignoring the old dictum "Absence of evidence is not
>>evidence of absence" and drawing a fallacious conclusion from an argumentum
>>ex silentio. Consider how little has actually survived from ancient Egypt, a
>>tiny fraction of all the evidence that may once have existed. It is wrong to
>>infer from this absence of evidence that, during the several millennia of
>>Egyptian history, there was no contact at all with other parts of the world,
>>or indeed the universe.
>
>I've never understood that 'old dictum'.
>Absence of evidence is in fact evidence of absence. Not proof, but
>evidence of the probability of absence.

You have just made two separate statements. Which one do you hold to
be correct?

Is it (1) Absence of evidence is evidence of absence, or is it
(2) Absence of evidence is evidence of the probability of absence?

> And how likely that is depends
>upon the context.

Assuming that you really know the context.
>
>For instance, if we find a certain type of fossil in a certain type of
>context on continent A, but we don't find it in a similar context on
>continent B, that suggests pretty strongly that the lack of fossils means
>a lack of the animal involved.
>

I take it that ultimately you tend towards statement (2). That
"Absence of evidence is evidence of the probability of absence". If
so, I would agree with you. However, as you know, I have many times
taken issue with those who argue for statement (1).

Philip Deitiker has made a valiant attempt to explain the problem in
terms of the binomial distribution and confidence limits and strictly
speaking he is correct. Unfortunately in the real world you rarely
have enough data to evaluate a problem in these terms and we have to
ultimately fall back on the truism that it doesn't mean that something
does not exist, just because we haven't found it yet.

Eric Stevens

From:	Doug Weller
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 22:49:02 +0000

On Fri, 21 Jan 2005 10:09:50 +1300, in sci.archaeology, Eric Stevens
wrote:

>On Thu, 20 Jan 2005 16:59:22 +0000, Doug Weller
> wrote:
>
>>On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier wrote:
>>
>>>
>>>Martyn is blatantly ignoring the old dictum "Absence of evidence is not
>>>evidence of absence" and drawing a fallacious conclusion from an argumentum
>>>ex silentio. Consider how little has actually survived from ancient Egypt, a
>>>tiny fraction of all the evidence that may once have existed. It is wrong to
>>>infer from this absence of evidence that, during the several millennia of
>>>Egyptian history, there was no contact at all with other parts of the world,
>>>or indeed the universe.
>>
>>I've never understood that 'old dictum'.
>>Absence of evidence is in fact evidence of absence. Not proof, but
>>evidence of the probability of absence.
>
>You have just made two separate statements. Which one do you hold to
>be correct?
>
>Is it (1) Absence of evidence is evidence of absence, or is it
>(2) Absence of evidence is evidence of the probability of absence?
>

To quote Alan Crozier, "Absence of evidence may not
be _proof_ of absence, but it can be _evidence_."
>> And how likely that is depends
>>upon the context.
>
>Assuming that you really know the context.
>>
>>For instance, if we find a certain type of fossil in a certain type of
>>context on continent A, but we don't find it in a similar context on
>>continent B, that suggests pretty strongly that the lack of fossils means
>>a lack of the animal involved.
>>
>
>I take it that ultimately you tend towards statement (2). That
>"Absence of evidence is evidence of the probability of absence". If
>so, I would agree with you. However, as you know, I have many times
>taken issue with those who argue for statement (1).

Perhaps it hangs on how you are defining evidence. I agree with Alan.

>
>Philip Deitiker has made a valiant attempt to explain the problem in
>terms of the binomial distribution and confidence limits and strictly
>speaking he is correct. Unfortunately in the real world you rarely
>have enough data to evaluate a problem in these terms and we have to
>ultimately fall back on the truism that it doesn't mean that something
>does not exist, just because we haven't found it yet.
>
And that is basically the way science works, isn't it? Any scientific
theory can be overturned by new evidence, but that doesn't mean 'anything
goes'.

Doug
--
Doug Weller -- exorcise the demon to reply
Doug & Helen's Dogs http://www.dougandhelen.com
A Director and Moderator of The Hall of Ma'at http://www.hallofmaat.com
Doug's Archaeology Site: http://www.ramtops.co.uk

From:	Steve Marcus
Subject:	Re: New subjectline: Valid and invalid arguments; former: Cocaine in ancient Egypt?
Date:	Thu, 20 Jan 2005 13:05:45 -0500

"Doug Weller" wrote in message
news:dgovu0tevvdikh1rcm4pgqv3s8frji7hnc@4ax.com...
> On Thu, 20 Jan 2005 15:01:57 GMT, in sci.archaeology, Alan Crozier wrote:
>
>>
>>Martyn is blatantly ignoring the old dictum "Absence of evidence is not
>>evidence of absence" and drawing a fallacious conclusion from an
>>argumentum
>>ex silentio. Consider how little has actually survived from ancient Egypt,
>>a
>>tiny fraction of all the evidence that may once have existed. It is wrong
>>to
>>infer from this absence of evidence that, during the several millennia of
>>Egyptian history, there was no contact at all with other parts of the
>>world,
>>or indeed the universe.
>
> I've never understood that 'old dictum'.
> Absence of evidence is in fact evidence of absence. Not proof, but
> evidence of the probability of absence. And how likely that is depends
> upon the context.

Exactly, Doug. This article contains a nice discussion of "absence of
evidence ... " as well the entire concept of "you've got to keep an open
mind."

http://www.csicop.org/si/9801/adler.html

>
> For instance, if we find a certain type of fossil in a certain type of
> context on continent A, but we don't find it in a similar context on
> continent B, that suggests pretty strongly that the lack of fossils means
> a lack of the animal involved.
>

Steve
--
The above posting is neither a legal opinion nor legal advice,
because we do not have an attorney-client relationship, and
should not be construed as either. This posting does not
represent the opinion of my employer, but is merely my personal
view. To reply, delete _spamout_ and replace with the numeral 3

> [SNIP]
>
> Doug
> --
> Doug Weller -- exorcise the demon to reply
> Doug & Helen's Dogs http://www.dougandhelen.com
> A Director and Moderator of The Hall of Ma'at http://www.hallofmaat.com
> Doug's Archaeology Site: http://www.ramtops.co.uk
>
>

From:	Philip Deitiker
Subject:	Meaning of Zero and All, Application to archaeology
Date:	Thu, 20 Jan 2005 20:14:03 GMT

I know that Alan was Joking, apparently Steve didn't catch on.
But on a more serious note. This is in response to Doug's reply

"
I've never understood that 'old dictum'.
Absence of evidence is in fact evidence of absence. Not proof, but
evidence of the probability of absence. And how likely that is
depends upon the context.
"

The other day I was in a 'chat' and an aquantance of mine
said to me 'what do they mean statistics, they never ask for
. . . . . . . .'

And as I was looking at a graph I made the point to the
indiviuals that zero statistically is not zero and 100% is
statistically not 100%.

This sounds a bit loonish, but it is actually not. This whole thing
started, for myself, about 3 years ago when I was doing the early
patient typing studies. Now at that time there were 362 HLA types
in and I was detecting 2 of a given HLA allele in my patient sample
of 24 and in 362 there were zero (caucasian american). Now at the
time I was niave and I was looking at the error values given in
biostatistcal analysis. However Zar does a very poor job of
explaining the problem. SE values for the ends of the binomial
probability distribution have no value what-so-ever. The confidence
ranges are not symmetrical.
Let me explain this. Suppose something has a frequency of 500/1000
in a population. I then sample 1000, i should get 500. Theoretically
no, one is the mean of what you could get 400 or 600 at some very low
frequency. So what if I am sampling that population and what if I get
500. While it may seem a good idea to choose the accumulated p values
from the low edge and high edge as the confidence range, this is
actually not the case. One actually needs to shift the frequencies of
both until the number you sampled is either .1587 (1 S.D. edge) from
both directions (IOW the probability that the frequency is X or lower
arriving at a Sample N and Y or higher arriving at the same sample N.
When one does this the freqeuncies within a stated confidence
interval widen slightly at the midrange frequencies (around 0.5) but
vary even more significantly at the edges.
Thus what happens if you have a 0S of N. The low end of frequencies
is 0 of course, the mean is zero, but the p of a frequency being
greater than 0 is a function of the confidence limit for any N. If N
increases the confidence range shrinks.

To make the clear, suppose you took 0N, the odds of having 0S is
100%. If you sample 1N, and get 0S. The f could equal 0.68 containing
a full 1 S.D. confidence interval. If the sample is 2N and one gets
0, the frequency that could explain that drops. The 68.3% confidence
limit for a sample of 0 in 76N = 0 to 0.015. For a sample of 0 in
3798 the 68.3% confidence interval of frequencies = 0 to 0.0003. What
you should note that relative confidence range for a sample of 0 is
infinity, and therefore the relative variance becomes meaningless,
where as in the midrange frequencies it is relatively useful for
simplifying statistical calculations. The point to be made is that a
zero frequency is only something approachable in confidence with
great N. This is not an artifact, it is something that scientist over
look because they assume that if absolute sample trend line is real,
then trends must intercept at zero or all. This may be true, anyway,
but it does not mean that the trend intercepts were they think it
intercepts. And confidence steps in to that arguments and begs the
question, what is the trend in your confidence range, and were does
that line intercept zero, if it intercepts at all.

An excellent example of this is extinct species. I can think of at
least 5 examples of where a species was declared extinct in the wild,
and it later showed up. Sampling efficiency and predatory prey
relationships are a possible reasoning for this error. Did the
persons who declared a species extinct consider the role of sample
size and confidence or did they, after not seeing a species for a
great while assume it was extinct. Extinction is exactly that no more
of a species exist, not no more observations of that species, if it
were thousands of newly discovered species would be considered
extinct until we find them. The coelecanth was once 'extinct'.

In terms of what Doug said, in order to use uncertainty to make the
case of a non-zero frequency when the sampled value is zero one has
to make the case for a trend line, whose confidence would project
from non-zero values vs sample parameter(time, geography, whatever)
that is not zero. For example we cannot project that little green men
from mars were here 2000 years ago because there is no trend line for
martians. In an argument concerning the onset of stone tool
manufactering in african 2.6 mya, it is possible, using confidence to
project stone use onset might have been 2.9 mya, and disputed fossils
might be representative. Confidence, of course, does not mean that
such things exist, only means that existence is possible based on the
variances in sampling and expected confidence in results.
For the specific example above, suppose you are sampling stone
tools. What is the frequency of stone tools per unit of time, what is
the frequency of hominid occupations in that area, the use of stone
tools per hominid frequency can be estimated. But both parameters are
subject to sample variance, and thus increase the confidence range
that you know what the frequency per hominid was. As one approaches
the time in which hominids first routinely used stone tools then the
sampling error, as evidenced above, becomes relatively huge, and the
trend line starts to swerve shy of the y=0 intercept.
Starting at the point were sample frequency of S events is less
than about 5 one has to increase the time frame of sampling to
capture enough events to result in a statistic > 0. So for instance
if you capture 1 event per .4 million years, it means that you had
1/4 of an event of .1 million years, the sampling range appropriate
later. But then if one goes say 1 million years without sample while
recovering numerous hominid bones, the combined absense of stone
tools can be predictive over the period. Or in Doug's words the
'context' of the statistic has to be shifted so that the zero value
takes on enough meaning.
Adding to this dicussion one may need to add statistics. For
example. Let us say that one has the expectation of speciation of
hominids and that typically new species form out of constrictions,
and you measure genetic sizes of contrictions in 1000s of individuals
and estimate their range. Then one can estimate an aspect of
speciation over time, the p that you are glimpsing a radiation that
followed a constriction. Once the unweighed parameters are derived
then you have to weigh in, are there biasing factors to suggest
speciation occurred at my sampling time. This creates one separate
confidence interval for changes in expected population size. This has
to be crossmultiplied by ones ability to sampled geography that
crossed such range areas, and fortuitous loss of material even in
those areas. One simple reasoning for increasing the range is if you
establish the minimal geogrpahic area for a nascent population, the
maximal limit of the 'constriction'tube, then one needs to then
measure, based on your saturation of geographies that might be in the
range of this species origin, what is the likelihood that the range
might be unsampled, and how long it might have been in that range
before radiating and thus the sample generators crossing the sampled
areas. The uncertainty created above increases the confidence range
and in particular increases markedly the sample range for a zero
sample. In the end one then could argue things like, well the longest
speciating constriction in 1/2 million years, and we have missed no
areas of africa that would contain such a population in say 1/4
million years and thus between 1/4 and 1/2 million years is the edge
confidence range for these factors, not factoring issues of hominid
density and sample efficacy, the interval may widen still be another
1/4 million years. This is an example were non-zero values may not be
interpreted as zero because of sampling errors.

To redress the issue that I introduced with. In the olds days we
did not use statistics greatly and almost never used confidence
intervals, you had an assay, you got a result you made a bar graph.
During the last 20 years though people have tried to cheat by using a
very small sample size. As a result most feilds of science have
gotten wise to statistical analysis and application of binomial
probability to sampling S versus N. As a result of this need in the
literature for greater qualification of results people have gotten
more sophisticated.