Annette, with respect to the first question, this article: http://content.nejm.org/cgi/content/full/355/20/2064, may not answer your question directly, but may still be of interest:
The author's concluding statement: "The challenge for medical practitioners is to remain aware that some of their psychiatric patients do in fact pose a small risk of violence, while not losing sight of the larger perspective - that most people who are violent are not mentally ill, and most people who are mentally ill are not violent." Miguel -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Sunday, September 07, 2008 4:16 PM To: Teaching in the Psychological Sciences (TIPS) Subject: [tips] Several questions (1) I talk with my intro students about the misconception that mentally ill people generally have a history of violence. And the research evidence seems to support this. But in thinking about where the misconception comes from, would it not be correct to say that most people with a history of violence have had a mental illness? In other words, could one be violent or have unmotivated violence and not be mentally ill? A more technical set of questions (1) Is it proper to talk about independent and dependent variables in a correlational study? And to what extent? Isn't it *more* correct to call the variables predictor and criterion variables?What is the current status of this language? (2) I have learned that a rule of thumb for evaluating the effect size of a significant correlation is to square r and this is a crude indicator of how much of the variability in the criterion variable comes from the predictor variable. I'd like to hear if this is too crude to be useable. Is there another, readily calculable effect size? I am very bothered by studies that make a big deal of a significant correlation of .2 or .3. Thanks Annette Annette Kujawski Taylor, Ph.D. Professor of Psychology University of San Diego 5998 Alcala Park San Diego, CA 92110 619-260-4006 [EMAIL PROTECTED] --- To make changes to your subscription contact: Bill Southerly ([EMAIL PROTECTED]) --- To make changes to your subscription contact: Bill Southerly ([EMAIL PROTECTED])
