Jeff...you may want to look at: Cohen, J. (1983). The cost of dichotomization. Applied psychological measurement, 7, 249-253.
Also, and unfortunately I don't have the cite handy, about 2 years ago McCallum et al did an article on dichotomization in Psychological Methods. hope this helps...dale Dale N. Glaser, Ph.D. Executive Manager, Strategic Research TrendSource 4891 Pacific Highway; Suite 200 San Diego, CA 92110 Phone: (619) 718-7467 (ext. 128) Fax: (619) 718-7490 Email: [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Dang, Jeff Sent: Tuesday, March 02, 2004 1:33 PM To: '[EMAIL PROTECTED]' Subject: [edstat] Continuous versus Dichotomous Edstat, I have personally found that a lot of health researchers like to aggregate normally distributed, continuous outcomes into dichotmous outcomes. In some cases, this is done because the researcher is more familiar with dicohotmous outcomes (disease/no disease) and seeks to interpret their results in terms of odds ratios within a logistic regression. In some cases, this can be problematic because you lose information. For instance those near the cut-off point are forced into one group or another. Thus, you exaggerate the differences for some individuals. If anybody on the listserv can refer me to articles related to this problem I would be most appreciative. Thank you. Jeff Dang . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . ================================================================= . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
