[Leica] Re: Mike's new religion

[Jim Brick <jimbrick@photoaccess.com>]

Truer words were never spoken Erwin.

It is an absolute fact, a fact supported by scientific endeavors throughout
time, that if you wish to prove a point, you collect data to support that
point. All other data is discarded. This, unfortunately, is why there are
so many untrue myths, unfounded scientific theories, and just plain old
incorrect beliefs.

It is human nature to want to be right. To NOT want to be proven wrong. And
to make certain that one can support his/her own beliefs, one selectively
collects his/her own facts and then makes broad statements based upon these
selected facts.

By looking at only the collected data, the "proposed fact" is, of course,
"proven" true.

This is indeed, how a "religion" is supported.

Jim


At 12:16 PM 1/17/00 +0100, Erwin Puts wrote:
>Mike J wrote in part:
>" ...Or, in other words, you know full well that you cannot tell a print
>>  made with a Leica lens from a print made with a Pentax lens. And you are
>>  absolutely correct in that assumption, I believe.
>>
>>  Any other response would have made me very surprised. Any lens expert
>>  knows that you cannot tell one brand of lens from another based only on
>>  real-world results"
>
>Well Mike: yours is a fine example of semantic armtwisting and 
>logical juggling. I said that your test is flawed, not in principle 
>but in execution. Your inference that by stating this I do 
>acknowledge that I do know that it is impossible to identify prints 
>made with a certain camera/lens combination is  a strong leap of your 
>imagination. And not justified I am afraid to say.  Your  gauntlet 
>test is set up to prove a hypothesis, that is what every test tries 
>to do. Now simple and time honored test procedures that are conducted 
>all over the world, give you the rules. Any test should be done in 
>such a way that only the variable you have identified as proving the 
>hypothesis should be the real and only variable. All other 
>influencing factors need to be kept constant or under control. 
>Secondly a control group with a placebo environment need to set up to 
>ascertain the validity of your setup. And most importantly: the 
>person designing the test should predict before the start of the test 
>what results are required to prove or disprove the hypothesis. This 
>prediction has not been published, making the test a -see-I-told-you- 
>exercise.
>The most misleading of your setup is the generality of your 
>hypothesis, that is: "you cannot tell a print
>made with a brand X lens from a print made with a brand Y lens". That 
>is you assume that a picture made with a 180mm lens at f/2 of brand X 
>cannot be told apart from a print made with a 35mm lens at f/8 of 
>brand Y? Your only selection criterium is the sharpness criterium 
>which is as subjective as can be.  This is a most unrealistic 
>assertion and shows that you are not really focused on a true and 
>meaningful test. Your mind is already made up: yours is not  an 
>interesting hypothesis, but already a statement of fact as you have 
>said above in the quote. Now it is very easy to conduct a session 
>that will prove you "right".  Show a group of persons ten prints 
>selected by the one who wants to prove himself right, include three 
>pictures made with brand X equipment  among the ten and here we go: 
>if 25% of guesses by the group of test persons correctly identifies 
>the brand X picture is your hypothesis OK. Or do we need 53% to make 
>the test meaningful. How big is the mere statistical chance that x% 
>will at random select the correct print?
>I am amazed, Mike, that you go to these lengths just to 'prove' your 
>point which is unprovable to start with. I did on purpose refer to 
>the "angels on a pin" discussion. When we are talking religion and 
>that is what you are doing all arguments and facts are futile. What 
>you want to get is support  for your own belief system and values. 
>Which is fine with me. But I graciously decline to be converted to 
>your religious beliefs.
>Your second statement ("Any lens expert knows that you cannot tell 
>one brand of lens from another based only on real-world results") is 
>again one of those sentences that look charmingly convincing but are 
>basically non substantive, like this one: "any political forecasting 
>expert knows that you cannot tell which candidate for president will 
>win the election based only on real-world results".Well it is the 
>charm of any attractive religion that people can repeat mantras that 
>are simple to remember and evoke the impression of deep significance. 
>Our language is a powerful instrument is it not?
>
>Erwin
>
>