Re: curriculum question

2005-11-03 Thread James J. Roper, Consultor - Tradutor
Bill (and others),

Interesting perspective.  I am a cynic too, but I take a different 
angle.  In my graduate-level biostatistics class here in Brazil, the 
students have to read and analyse papers that are using the particular 
analysis that we are working on that week.  I am amazed at the bad 
statistics, as you are.  Regressions that are really correlations, 
ANOVAS that should have been regressions, incomprehensible multivariate 
analyses, complete failure to attend to the assumptions, hypotheses that 
will be rejected by definition and not by compliance with (or not) 
theory.  The students all feel like, since they are reading most papers 
in English, that they are the ones who don't understand, thinking that 
all these published papers in many important journals must have gotten 
published because they were well-written.  I have to teach them that, 
surprising though it may be, these papers have flaws from small to large.

HOWEVER, when well-done, statistics clear the confusion.  After all, 
psychologists show that people see patterns where they do not exist.  I 
would say that the "obvious" patterns do not necessarily need 
statistics, and the self fulfilled prophecies do not either.  However, 
those kinds of results are boring and obvious.  They were probably 
predictable on general principles and the laws of physics.

The not-so-obvious results are the ones that are interesting, and those 
are also the ones that need statistics to make sure that we are not 
seeing patterns that do not exist.  Without and idea of sampling error 
and variance, our intuition over whether a pattern exists is 
error-prone.  The only way to control that error is statistics and 
well-defined studies.

So, I say, we need to force the scientific and ecological community to 
learn how to use the tools of the trade.  Nobody need to be immersed in 
statistics to understand the rules.  But, if a person has not taste or 
patience for statistics, then I suggest that they find a good 
collaborator who knows statistics well.  After all, in most of my 
helping students develop projects, because of my statistical 
understanding, I save them all time and frustration.  The sample size 
required to show a pattern is much easier to calculate with a knowledge 
of statistics, for example.

Cheers,

Jim

Bill Silvert wrote:

>I didn't expect much agreement with my posting, and I'll just comment on two 
>points that Roper raises, interspersed with his posting below:
>
>  
>

=
Consulto ECONCIÊNCIA
Ecologia, Conservação, Ciência e Consciência!
Consulting, specializing in Conservation
Research Methods, Analysis and Translations.

  http://www.montanhaviva.org/ecosci/
=
James J. Roper, Ph.D.
Caixa Postal 19034
81531-990 Curitiba, Paraná, Brasil
-
E-mail:   [EMAIL PROTECTED]
Phone/Fone/Teléfono:   55 41 33857249
celular:   55 41 99870543
e-fax:1-206-202-0173 (in the USA)
-
Ecologia e Conservação na UFPR
http://www.bio.ufpr.br/ecologia/





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Re: curriculum question

2005-11-02 Thread James J. Roper, Consultor - Tradutor
At the risk of repeating another opinion, I could not think that Bill 
could be more wrong!

A skill in any field comes from knowing how to use the tools.  I would 
take Bill to task to "prove" what he says about little value from 
statistical analysis.  Every really good paper published in Ecology and 
many other ecological journals required the statistics that was included 
to make their point.

Sure, there are many bad examples of statistics, and I would bet that 
Bill is also wrong about most ecologists being able to spout ANOVA and 
t-tests in their sleep!  And, Bill goes on to contradict himself when he 
says:

"In terrestrial work where 
sampling tends to be easier and one can lay out quadrats on foot, etc., 
statistical methods can be very useful."

Also, where he says that

The literature of the field is full of schemes for stratified random sampling 
and negative binomial distributions, but virtually no real ecology.

This problem is NOT due to statistics, but rather the particular 
situation.  And, could it be that those in this field don't know their 
tools or their theory?

And, if we were to wait for good teachers, many other things would be 
forgotten!  What we need are good learners and self-learners.  
Statistics, to be useful, must be understood and anybody who uses tools 
well, understands those tools.  Otherwise they should hire out.

Jim

Bill Silvert wrote:

>At the risk of repeating myself I feel compelled to respond to Ryan Walker's 
>post. Unless the teaching of statistics can be totally changed, I would 
>argue for less statistics, not more. As I have pointed out before, most 
>ecologists can spout ANOVA and t-tests in their sleep, but almost none can 
>do something as basic as adding two numbers (remember my earlier post about 
>adding 100+-3 to 200+-4?). Most statistics courses deal exclusively with 
>linear models to the extent that the majority of books I have surveyed hew 
>to the old line that transformations are for the purpose of linearising data 
>(they should be used to normalise variances).
>
>Over all I have seen little of value come out of statistical analyses, which 
>usually just confirm the obvious, but I have some incredibly stupid 
>conclusions drawn from incorrect use of statistics. In balance I think that 
>the value of statistics is not significantly greater than zero, if indeed it 
>is positive at all.
>
>Of course this can vary with the subfield. In terrestrial work where 
>sampling tends to be easier and one can lay out quadrats on foot, etc., 
>statistical methods can be very useful. The use of statistical models in the 
>design of agricultural experiments is clearly essential for example. But in 
>areas where data are collected in a more opportunistic way the use of 
>statistics is often a diversion rather than a help. In aquatic ecology, and 
>especially biological oceanography, statistics can be a real nuisance - if 
>anyone ever captured the Loch Ness monster they couldn't publish the news 
>because one is not statistically significant!
>
>For a particular example of what I mean, look at fisheries oceanography. The 
>literature of the field is full of schemes for stratified random sampling 
>and negative binomial distributions, but virtually no real ecology. 
>Basically the statistics has edged out the ecology, and it is too hard to do 
>both.
>
>Bill Silvert
>
>
>- Original Message - 
>From: "Walker, Ryan" <[EMAIL PROTECTED]>
>To: 
>Sent: Tuesday, November 01, 2005 6:18 PM
>Subject: Re: curriculum question
>
>
>  
>
>>Having come from a good undergraduate program (University of Wisconsin - 
>>Stevens Point) and working on a graduate degree at a university with a 
>>somewhat lacking undergraduate program (Texas Tech University), I have 
>>seen both sides of the coin.  Regardless of the focus of the program 
>>(Ecology, Wildlife Management, etc.), there is a general need for more 
>>statistics and experimental design.  My undergraduate program was more 
>>focused on management and techniques of wildlife ecology and its limited 
>>statistical requirements are still more than other programs.  Focusing on 
>>statistics that may be useful for students to know, such as 
>>non-parametrics and multi-variate analyses.  I realize that students may 
>>have difficulty grasping some of these more complicated topics, but I feel 
>>it is necessary to expose students to this material.  A simple knowledge 
>>of the tools that are available for research would be extremely helpful. 
>>
>>
>
>
>
>  
>

-- 
Atenciosamente,

James

=
Consulto ECONCIÊNCIA
Ecologia, Conservação, Ciência e Consciência!
Consulting, specializing in Conservation
Research Methods, Analysis and Translations.

  http://www.montanhaviva.org/ecosci/
=
James J. Roper, Ph.D.
Caixa Postal 19034
81531-990 Curitiba, Paraná, Brasil
-
E-mail:   [EMAIL PRO