I am sure that we would all hope that the real "issue" is scientific, and not religious....
Just to clear up some confusion - plots are often absolutely necessary to convey results and to see patterns. Statistics are often absolutely necessary to understand or confirm pattern. People have been known to see patterns in randomness, so our "intuition" about pattern can mislead. Psychologists have tested people to look and see pattern in a random collection of circles of various colors and sizes. People found patterns where none existed. This only tells us that we should be careful when we think we perceive pattern. If we think we perceive pattern in data that wa= s not collected to test that pattern, we should generate new tests to specifically test for those patterns. Statisticians are often not biologists, so while they may know what what they are doing, they often do not know biology. Also, I am finding more an= d more that people are forgetting how to do simple math! If they can't do th= e calculation on their computer, they can't do the calculation.... Finally, I have been having my biostatistics students read papers that include the topic of the week - we have found so many errors in analysis that the poor Brazilian students who do not read English well, and assume that not the author erred, but rather they erred in thinking that the stats was bad. I would guess that as many as 50% of the papers have from mild to serious mistakes. Scarey! So, the moral of the story is, look at well-done figures, then check your conclusions with appropriate statistics, if necessary. But always doubt. Cheers, Jim On 7/19/07, William Silvert <[EMAIL PROTECTED]> wrote: > > Although this is really a religious rather than scientific debate which i= s > unlikely to lead to any concensus, I want to respond to some of Jim > Roper's > comments. > > The fact that you can learn a lot by looking at plots does not mean the > that > "results are so glaringly obvious". Humans are very good at pattern > recognition and often can see what is present in a plot better than they > can > analyse numerical data. Also, plots often show unexpected features which > lead to new knowledge - they are not just for hypothesis testing. > > On several occasions I have been consulted by people who are quite expert > at > statistics who cannot interpret their data, and who were surprised that b= y > plotting the results in the right way a clear answer leaped out at them. > Of > course they then had to confirm the results with statistics, but that is > mainly to get the paper past referees. > > Jim ends with the usual comment that if the statistics are carried out by > someone who is really good at stats, the results will be good. That may b= e > true, but good statisticians are pretty rare beasts, and in the average > lab > the plotting method is just as reliable as textbook stats. Some of you ma= y > recall a post of mine a couple of years ago where I surveyed a lot of > statistically sophisticated fisheries scientists to see if they could add > two numbers (what is 100+-3 + 100 +-4?) and only one person came up with > the > answer - but he was very unsure of himself, and couldn't figure out how t= o > multiply the numbers. > > Just a glance through any journal will quickly show that most biologists > have little idea of significance and represent their results with > exaggerated precision. In a perfect world maybe we could trust all > statistical analyses, but we ain't there yet. > > Bill Silvert > > > ----- Original Message ----- > From: "James J. Roper" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Wednesday, July 18, 2007 3:43 PM > Subject: Re: ECOLOGY Mathematics and the metamathematics of evasive > ecology? > Re: Request: Data sets for biocalculus project > > > > Mattheus, > > > > You are showing some misunderstanding of the use of statistics. A few > > observations. > > > > 1. If your results are so glaringly obvious, then the question was > > probably not very interesting, or a logical consequence of the methods. > > > > 2. Questions that are not so simple need statistics to discover the > > probability of something happening when it is not obligatory that it > > happen. > > > >> statistical tests when you can simply draw a plot and > >> your conclusion comes? > > 3. A plot can mislead. > >> I need to learn that populations must > >> be normal, they must be homoscedastic, there are at > >> least 3 models for ANOVA, there is something out there > >> with the name of ANCOVA, and I have no single idea if > >> this is useful for me or not... > --=20 James J. Roper, Ph.D. Ecologia e Din=E2micas Populacionais de Vertebrados Terrestres ------------------------------ Caixa Postal 19034 81531-990 Curitiba, Paran=E1, Brasil ------------------------------ E-mail: [EMAIL PROTECTED] Telefone: 55 41 33857249 Mobile: 55 41 99870543 ------------------------------ Ecologia e Conserva=E7=E3o na UFPR <http://www.bio.ufpr.br/ecologia/> Econci=EAncia - Consultoria e Tradu=E7=F5es <http://jjroper.googlespages.co= m>
