Comments on: appealing eyes == powerful method http://hea-www.harvard.edu/AstroStat/slog/2008/appealing-eyes-powerful-method/ Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders Fri, 01 Jun 2012 18:47:52 +0000 hourly 1 http://wordpress.org/?v=3.4 By: vlk http://hea-www.harvard.edu/AstroStat/slog/2008/appealing-eyes-powerful-method/comment-page-1/#comment-362 vlk Sat, 13 Sep 2008 15:10:43 +0000 http://hea-www.harvard.edu/AstroStat/slog/?p=604#comment-362 You also make a very good point when you say <em>Prior to getting rid of unpleasant data points, making graphics appealing and saying an excellent results from statistics, I wish they give a second thought about outliers or statistical lexicons carefully</em> I have found that astronomers are generally unable to judge the comparative powers of different tests. This is not surprising, because we aren't trained for it. So for instance when two tests may give apparently contradictory answers, we can't tell which one to believe. The answer, of course, is to always go with the more powerful one. But of course, that's easier to say than to do. You also make a very good point when you say
Prior to getting rid of unpleasant data points, making graphics appealing and saying an excellent results from statistics, I wish they give a second thought about outliers or statistical lexicons carefully

I have found that astronomers are generally unable to judge the comparative powers of different tests. This is not surprising, because we aren’t trained for it. So for instance when two tests may give apparently contradictory answers, we can’t tell which one to believe. The answer, of course, is to always go with the more powerful one. But of course, that’s easier to say than to do.

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By: vlk http://hea-www.harvard.edu/AstroStat/slog/2008/appealing-eyes-powerful-method/comment-page-1/#comment-361 vlk Sat, 13 Sep 2008 15:03:57 +0000 http://hea-www.harvard.edu/AstroStat/slog/?p=604#comment-361 Ah, I don't think that is a correct characterization, Hyunsook. Astronomers do <em>not</em> use eyeballs to claim that this or that test works well. I'm afraid that I may be to blame for this wrong impression because I keep saying that there is no statistical test that can match the human eye. By which I actually mean the human brain, in its ability to recognize patterns. The converse to that is that the brain is easily fooled into seeing patters that don't exist, and yes, we are well aware of that. In fact that is why we ask for more and better statistical analyses, and rely on those to gain confidence in our results. I do admit however that the concept of statistical power is not all that familiar to astronomers. We think of that usually in the context of probability of detection, and not much else. However, it is also true that most statistical techniques that exist currently are far too general and simpleminded to deal with the complexities enountered daily in astronomical data. It would be foolish to expect, say, that a local detect method would work as well as a human to tag and identify coronal loops in a <a href="http://xrt.cfa.harvard.edu/" rel="nofollow">Hinode</a> image. So naturally we develop a bs detector to tell whether some test or technique is not working. But don't mistake that for rigorous analysis! Ah, I don’t think that is a correct characterization, Hyunsook. Astronomers do not use eyeballs to claim that this or that test works well. I’m afraid that I may be to blame for this wrong impression because I keep saying that there is no statistical test that can match the human eye. By which I actually mean the human brain, in its ability to recognize patterns. The converse to that is that the brain is easily fooled into seeing patters that don’t exist, and yes, we are well aware of that. In fact that is why we ask for more and better statistical analyses, and rely on those to gain confidence in our results.

I do admit however that the concept of statistical power is not all that familiar to astronomers. We think of that usually in the context of probability of detection, and not much else. However, it is also true that most statistical techniques that exist currently are far too general and simpleminded to deal with the complexities enountered daily in astronomical data. It would be foolish to expect, say, that a local detect method would work as well as a human to tag and identify coronal loops in a Hinode image. So naturally we develop a bs detector to tell whether some test or technique is not working. But don’t mistake that for rigorous analysis!

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