FRIHOST • FORUMS • FAQ • TOS • BLOGS • DIRECTORY
You are invited to Log in or Register a Frihost Account!

Baloney Detection

   Frihost Forum Index -> Science -> General Science
 


Bikerman
The late lamented Carl Sagan wrote a useful set of rules which one could call a bull***t or Baloney Detection kit. I think it is worth posting this here since it is at least as relevant now as when it was written.

If you want to test something then the following are a good way to set about it.

# Wherever possible there must be independent confirmation of the facts
# Encourage substantive debate on the evidence by knowledgeable proponents of all points of view.
# Arguments from authority carry little weight (in science there are no "authorities").
# Spin more than one hypothesis - don't simply run with the first idea that caught your fancy.
# Try not to get overly attached to a hypothesis just because it's yours.
# Quantify, wherever possible. Numbers not opinions or guesses.
# If there is a chain of argument every link in the chain must work.
# "Occam's razor" - if there are two hypothesis that explain the data equally well, choose the simpler.
# Ask whether the hypothesis can, at least in principle, be falsified (shown to be false by some unambiguous test). In other words, it is testable? Can others duplicate the experiment and get the same result?

When considered with the list of fallacies that I posted some time ago, this is a powerful tool to keep you on the straight and narrow.

Regards
Chris
Indi
Bikerman wrote:
# "Occam's razor" - if there are two hypothesis that explain the data equally well, choose the simpler.

That's not Ockham's Razor.
Bikerman
Indi wrote:
Bikerman wrote:
# "Occam's razor" - if there are two hypothesis that explain the data equally well, choose the simpler.

That's not Ockham's Razor.


True. Occam states :
entia non sunt multiplicanda praeter necessitatem
(entities should not be multiplied beyond necessity).
I would argue that the current meaning of the razor also includes
Quote:

when multiple competing theories have equal predictive powers, the principle recommends selecting those that introduce the fewest assumptions and postulate the fewest hypothetical entities
(Wikki)

I would further argue that 'fewest assumptions and 'fewest hypothetical entities' is reasonably abbreviated by 'simplest', although, to be sure, it is not semantically exact.

Chris.
DoctorBeaver
I agree with bikerman about the razor. I've always taken it to mean "choose the simplest option".
Bikerman
DoctorBeaver wrote:
I agree with bikerman about the razor. I've always taken it to mean "choose the simplest option".


Indi is correct, though, and I have to admit that the meaning is not exactly the same if it can be shown that fewer entities and fewer assumptions can produce a more complex output path. That would mean that simplest is not necessarily fewest simple steps...Hmmm......

I think I might be able to show this myself with reference to a simple deterministic system with feedback (producing chaotic output).

I'll have to work on it to get it to a realistic example.....hmmm....set me thinking.....I'm assuming that 'simple' in the way I used it would possibly mean 'most obviously deterministic or easily calculated' and that if this can be shown to be different from fewest steps with simple components, then my simplification fails.

Take a magnet on a rigid pole free to move in the x-y plane. Stick 3 magnets on the table and arrange the pole so that the moving magnet hangs about 2 inches above the desk. Let it go and predict what path it will take....That's a very simple chaotic system. It comprises deterministic elements of great simplicity - a pendulum and a constant magnetic field of known strength, yet produces an outcome which is completely non-deterministic in some circumstances.

Hmmm.....definitely food for thought.....

Chris.
Indi
Bikerman wrote:
DoctorBeaver wrote:
I agree with bikerman about the razor. I've always taken it to mean "choose the simplest option".


Indi is correct, though, and I have to admit that the meaning is not exactly the same if it can be shown that fewer entities and fewer assumptions can produce a more complex output path. That would mean that simplest is not necessarily fewest simple steps...Hmmm......

Perhaps the most extreme example is a god.

Suppose you wanted a theory to explain X. You come up with a theory that explains X, but requires advanced vector calculus in four dimensions, three spatial and one time, systems of simultaneous differential equations, definitions of abstract concepts like eigenspaces and imaginary numbers, etc. etc. etc. (By the way, that's not quantum mechanics, all of that is just to explain the motion of a bunch of balls connected by springs.)

Someone else comes along and says "god made it happen".

Clearly their theory is simpler. If Ockham's Razor were really that the simplest hypothesis should be selected, then we should select the latter. But that's not what Ockham's razor is about at all. When choosing among multiple hypotheses that all explain the phenomenon equally well, you should select the hypothesis that requires the fewest assumptions. That is Ockham's Razor, and in this case, that heuristic selects the former hypothesis because the latter includes an assumption of a god (actually, it includes LOTS of hidden assumptions, but that one is key).

Psuedoscientific hucksters love to point out that their pet "theories" are more often than not "simpler" than the actual scientific explanation, then argue by Ockham's Razor (although they rarely explicity name it) that that must mean their theory is true. So not only is it not semantically exact to say "simple", it's downright wrong, and that definition has been used to mislead and argue for pseudoscientific nonsense for ages. Using it in a bullshit detector seems counterproductive to me.

If you want to simplify Ockham's Razor, a more correct way to do so is to say if there are two hypotheses that explain the observations equally well, choose the one with the fewest assumptions. Still not technically correct, but at least it's not wrong.
Bikerman
Indi wrote:
Bikerman wrote:
DoctorBeaver wrote:
I agree with bikerman about the razor. I've always taken it to mean "choose the simplest option".


Indi is correct, though, and I have to admit that the meaning is not exactly the same if it can be shown that fewer entities and fewer assumptions can produce a more complex output path. That would mean that simplest is not necessarily fewest simple steps...Hmmm......

Perhaps the most extreme example is a god.

Suppose you wanted a theory to explain X. You come up with a theory that explains X, but requires advanced vector calculus in four dimensions, three spatial and one time, systems of simultaneous differential equations, definitions of abstract concepts like eigenspaces and imaginary numbers, etc. etc. etc. (By the way, that's not quantum mechanics, all of that is just to explain the motion of a bunch of balls connected by springs.)

OK...no problem so far...
Quote:

Someone else comes along and says "god made it happen".
Clearly their theory is simpler. If Ockham's Razor were really that the simplest hypothesis should be selected, then we should select the latter. But that's not what Ockham's razor is about at all. When choosing among multiple hypotheses that all explain the phenomenon equally well, you should select the hypothesis that requires the fewest assumptions. That is Ockham's Razor, and in this case, that heuristic selects the former hypothesis because the latter includes an assumption of a god (actually, it includes LOTS of hidden assumptions, but that one is key).


That last statement is the key indeed. The God solution is not an acceptible solution since it offers no explanation, only an assertion unsupported in scientific terms by either logical chain of reasoning or experimental observation. Clearly the possible solutions on offer must conform to the basic definition of a solution. If I were to look at this simply using my (actually it was Sagan's original wording I used, but I'll defend it) wording then the God solution would be less simple than the math solution because it would contain complexities which were not explained in the solution.
Quote:

Psuedoscientific hucksters love to point out that their pet "theories" are more often than not "simpler" than the actual scientific explanation, then argue by Ockham's Razor (although they rarely explicity name it) that that must mean their theory is true. So not only is it not semantically exact to say "simple", it's downright wrong, and that definition has been used to mislead and argue for pseudoscientific nonsense for ages. Using it in a bullshit detector seems counterproductive to me.

I take the point but I think you are being too harsh in judgement. Simple follows the words :-
Quote:
if there are two hypothesis that explain the data equally well

The God solution does not explain the data well at all since it offers no predictive basis on which to formulate experiment to test it and it simply uses a more complex entity than was the subject of the problem.
The way Sagan worded it is actually not far from the Positivist school with Mach's Principle of Economy :
Quote:
"Scientists must use the simplest means of arriving at their results and exclude everything not perceived by the senses."

I'm not a Positivist myself but it's an interesting aside.

On the main point, I see your objection to 'simplest' but I don't accept that it could be misused in the manner of your example, unless the person had no understandning of sicentific method. I assume the word is being applied to mean 'least unknown or assumed steps' - complexity.

I should, though, certainly have tightened up Sagans language in the other part of the statement because that is certainly wrong. It should perhaps read as :
"when you have two competing theories which make exactly the same predictions, the one that is simpler is the better."

That, I would argue, is the way most scientists would phrase and use the razor.

Quote:

If you want to simplify Ockham's Razor, a more correct way to do so is to say if there are two hypotheses that explain the observations equally well, choose the one with the fewest assumptions. Still not technically correct, but at least it's not wrong.


Hmm...the 'equally well' is still a problem though since that is still stronger than the original which has the 'same explanation' rather than allowing for potentially different ones. This is actually a statement of the Law od Parsimony isn't it ?

All in all I understand your objection to the wording, don't entirely agree with it, since in science I think the word 'simple' is rigidly enough understood to rule out pseudo-solutions like the one examined.

Einstein is credited with the version :
Quote:
"Everything should be made as simple as possible, but not simpler."

Which I like

Regards
Chris
Indi
Bikerman wrote:
Quote:

Someone else comes along and says "god made it happen".
Clearly their theory is simpler. If Ockham's Razor were really that the simplest hypothesis should be selected, then we should select the latter. But that's not what Ockham's razor is about at all. When choosing among multiple hypotheses that all explain the phenomenon equally well, you should select the hypothesis that requires the fewest assumptions. That is Ockham's Razor, and in this case, that heuristic selects the former hypothesis because the latter includes an assumption of a god (actually, it includes LOTS of hidden assumptions, but that one is key).


That last statement is the key indeed. The God solution is not an acceptible solution since it offers no explanation, only an assertion unsupported in scientific terms by either logical chain of reasoning or experimental observation. Clearly the possible solutions on offer must conform to the basic definition of a solution. If I were to look at this simply using my (actually it was Sagan's original wording I used, but I'll defend it) wording then the God solution would be less simple than the math solution because it would contain complexities which were not explained in the solution.

I said nothing about predicability because it doesn't apply in this context. The question was: given two theories that explain a phenomenon equally well, which one should be selected?

Both theories explain the phenonemon. One offers a quantitative mathematical explanation. The other offers a holistic, qualitative explanation. Neither theory is complete. The god theory does not explain where god comes from, and the mathematical model does not explain where mass and solid matter come from, or why the spring constant is in fact constant, and many other things. While it is true that attempting to explain the characteristics of a god-entity might be difficult, consider in comparison attempting to explain the mechanics of atomic lattice structures in the springs, the force-distance relationship of the chemical bonds between them, the dual wave-particle nature of the subatomic matter, the transmission of force by particles, some of them currently theoretical, etc. etc. etc.

You claim that all of that is "simpler" than just saying "there is a metaphysical intelligent being that controls everything according to its whims"? Others would disagree, and I would tend to be on their side. While it is true that the mathematical model is - to a point - predictive while the religious one is not, predicability is a separate metric that is unrelated to Ockham's Razor.

The reason the god hypothesis is rejected by Ockham's Razor is not because of "simplicity", which is an arbitrary measure at best (although I would say that any theory that can be explained in two or three sentences is probably far simpler than one that requires quantum mechanics). It is rejected because there is no requirement for the introduction of another hypothetical entity - the god - when the mechanics of the system can be described using existing entities that have already been observed directly, such as the proportinality of the spring extension to force for the lower force range. The god theory has unnecessary assumptions, in that it postulates hypothetical entities that the other theory does not require, while not improving the quality of the explanation. That's how Ockham's Razor works.

Bikerman wrote:
I take the point but I think you are being too harsh in judgement. Simple follows the words :-
Quote:
if there are two hypothesis that explain the data equally well

The God solution does not explain the data well at all since it offers no predictive basis on which to formulate experiment to test it and it simply uses a more complex entity than was the subject of the problem.

You are confusing predictive power with explanatory accuracy. Predictive power is unrelated to Ockham's Razor - a theory may be superior by Ockham's Razor even though it has no predictive value, or it may have fantastic predictive value but fail Ockham's Razor - a theory must be evaluated on both heuristics separately, they are orthogonal metrics.

The god theory has no predictive value. Nevertheless it actually explains the phenomenon better than the mathematical model. The mathematical model introduces dozens and dozens of questions, some of which have yet to be answered - and it still doesn't perfectly explain experimental data. It may be close, but there is always some error. The god theory, on the other hand, is a perfect explanation of what is happening (perfect because it uses post-hoc information, so it is always correct by definition), and goes on to answer other questions, such as why it's happening. It may not be able to predict the behaviour (without modification), but it sure explains it perfectly after the fact.

Bikerman wrote:
On the main point, I see your objection to 'simplest' but I don't accept that it could be misused in the manner of your example, unless the person had no understandning of sicentific method. I assume the word is being applied to mean 'least unknown or assumed steps' - complexity.

I should, though, certainly have tightened up Sagans language in the other part of the statement because that is certainly wrong. It should perhaps read as :
"when you have two competing theories which make exactly the same predictions, the one that is simpler is the better."

That, I would argue, is the way most scientists would phrase and use the razor.

Sagan was hardly the first to phrase it that way, but that doesn't make it right. Most scientists are actually unaware of the actual mechanics of how science accumulates knowledge (rather like most TV repairmen don't understand the actual mechanics of a plasma display, and Ockham's razor in particular is generally poorly understood. It is thanks to peer review that poor understanding of Ockham's Razor is generally not an issue in practice - the 10% that do understand the proper way to apply Ockham's Razor will correct the other 90% whenever "simplicity" is simply not a good enough metric.

Bikerman wrote:
Quote:

If you want to simplify Ockham's Razor, a more correct way to do so is to say if there are two hypotheses that explain the observations equally well, choose the one with the fewest assumptions. Still not technically correct, but at least it's not wrong.


Hmm...the 'equally well' is still a problem though since that is still stronger than the original which has the 'same explanation' rather than allowing for potentially different ones. This is actually a statement of the Law od Parsimony isn't it ?

Ockham's Razor is the principle of parsimony. While Ockham did not intend for it to be used to to select between competing theories (he intended it to be used to whittle the unnecessary components out of a single theory), that is the way we use it today. Parsimony does not equal or imply simplicity, it only implies sparsity. A theory that is remarkably complex with only a few hypothetical entities is better by Ockham's Razor than a theory that is very simple with many hypothetical entities.

Bikerman wrote:
All in all I understand your objection to the wording, don't entirely agree with it, since in science I think the word 'simple' is rigidly enough understood to rule out pseudo-solutions like the one examined.

Rigidly enough understood by whom?

You say that the mathematical model of the spring system is "simpler" in your opinion than the god theory. *shrug* Ok, sure, if you say so. (You haven't correctly ruled out the god theory by "simplicity" either, you used predictive power as the metric, which is something else entirely, but that's not important here.) But I feel compelled to ask who you're writing your guide for? Is it for mathematicians and scientists? Or is it for average people? And, if the latter, which of the two theories do you think the average person would find "simpler"? They may not think of mathematical or physical "simplicity" or "beauty" (to use Dirac's term) in the same way that you do. Rather than confusing the issue and continuing to spread an incorrect definition of Ockham's Razor, why not just take the opportunity to get it right and say "don't put anything in theories that doesn't need to be there, and when choosing between theories, pick the one with the fewest unproven theoretical constructs".
Bikerman
[modified this because I posted it when lacking sleep and feeling lousy]

All this stuff about predictivity and occam is a complete red herring. I was not suggesting that it be used as part fhe occam decision. I was suggesting that your acceptance that the two explanations are 'evenly' matched is not supportable. Since you brought up metrics then OK...what metrics are you uising for the first part of occam > Ie how do you decide whether the theories are both equally valid? Your example seems to just accept the God hypothesis is as valid as the science one and move straight to testing. My argument was that I do not accept that since without a system of comparison this is even more subjective than my version. All that stuff about Predictability is irrelevant since I'm applying it where it belongs .. at the gateway to occum , as a test of the validy of your assumption that the two theories are equally valid. Predictability has served science well in this regard so it seems reasonable to include it as a possible metric.
Your definition of explain is also a bit vague. You accept that if someone postulates a divinity that this explains something ? It does nothing of the sort. Explain means make understandable. How can you eff the ineffible ?
You didn't mention the next part of the paragraph where I say - OK, I'll assume that we are right to use occum. How would the two theories do ? I explained in the one paragraph the reason that it would fail all three version, not just yours. I thought my words were well chosen, apposite and information dense.
As I said - 1 reason is numbers, God is an extra entity which rules him out in your formulation.
He is ruled out on simplicity with no bother at all. I read your 'scarey' list of science with a smile. When you consider an infinite Deity and you suggest that some physics theories are more complex than the idea of a non-material eternal 'something' - I think you must be joking or trying to wind me up. It cannot be a seriousa proposal and I'm not going to waste time hunting references to complexity theory and various theorems and definitions because, frankly, I've now had enough of this pedantic, ill-humoured, arrgant and, above all,. So he fails my version of occam on complexity no bother at all.

Which verion ?
We know that one version in latin is the one I quuted up top. We also know that Occam would have picked this up from the times and peoples - he certainly didn't invent or first discover the concept.

Regards
Chris
Reply to topic    Frihost Forum Index -> Science -> General Science

FRIHOST HOME | FAQ | TOS | ABOUT US | CONTACT US | SITE MAP
© 2005-2007 Frihost, forums powered by phpBB.