The missing piece is why there are two clusters. There is most likely a two-level factor distinguishing the groups that was not included in the model. It might not even have been measured and now you need to find it. Rich
stat question - not R question so ignore if not interested
4 messages · Richard M. Heiberger, Jonathan Baron, Bert Gunter +1 more
A classic example used by my colleague Paul Rozin (when he teaches Psych 1) is to compute the correlation between height and number of shoes owned, in the class. Shorter students own more shoes. But ...
On 12/05/06 16:34, Richard M. Heiberger wrote:
The missing piece is why there are two clusters. There is most likely a two-level factor distinguishing the groups that was not included in the model. It might not even have been measured and now you need to find it. Rich
Jonathan Baron, Professor of Psychology, University of Pennsylvania Home page: http://www.sas.upenn.edu/~baron Editor: Judgment and Decision Making (http://journal.sjdm.org)
... But of course this is always the question underlying all empirical -- or maybe even scientific -- analysis: is there some other perhaps more fundamental variable out there that I'm missing that would explain what's "really" going on? I clearly remember George Box commenting on this in his Monday night beer and statistics sessions: after you're done and perhaps have written up and presented your (intricate!) analysis, you're always worried that someone might come along and say, "Well, did you consider...?" Cheers, Bert Bert Gunter Genentech Nonclinical Statistics South San Francisco, CA 94404 -----Original Message----- From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Jonathan Baron Sent: Tuesday, December 05, 2006 1:45 PM To: Richard M. Heiberger Cc: r-help at stat.math.ethz.ch; C. Park; Leeds,Mark (IED) Subject: Re: [R] stat question - not R question so ignore if not interested A classic example used by my colleague Paul Rozin (when he teaches Psych 1) is to compute the correlation between height and number of shoes owned, in the class. Shorter students own more shoes. But ...
On 12/05/06 16:34, Richard M. Heiberger wrote:
The missing piece is why there are two clusters. There is most likely a two-level factor distinguishing the groups that was not included in the model. It might not even have been measured and now you need to find it. Rich
Jonathan Baron, Professor of Psychology, University of Pennsylvania Home page: http://www.sas.upenn.edu/~baron Editor: Judgment and Decision Making (http://journal.sjdm.org) ______________________________________________ R-help at stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
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