A p of .05 does not automatically mean that 5% of the positive results are false positives. It just means that on any given test (if everything else is correctly done) there's a probability of .05 that you're getting a false positive.
Add to that the fact that in many pieces of research the obtained p of getting those results is far below .05. In my mind I think of it a lot like the Gamblers' Fallacy. They're (or should be) independent events. m -- Marc Carter, PhD Associate Professor of Psychology Chair, Department of Behavioral and Health Sciences College of Arts & Sciences Baker University -- From: Michael Burman [mailto:[email protected]] Sent: Monday, April 02, 2012 9:36 AM To: Teaching in the Psychological Sciences (TIPS) Subject: re: [tips] Frequency of Type I errors in published research. I get a sense that I'm going to regret asking this question, but why wouldn't setting the alpha value at .05 result in about 5% false positives in the literature? Are people suggesting that the true false positive rate would be lower? I get why it would be higher (statistical tricks, bias, research short cuts, etc), but not why it would be lower. Mike ------- Michael A Burman Ph.D. Assistant Professor Dept. of Psychology K-12 Outreach Coordinator for the Neurosciences University of New England 328 Decary Hall 207-602-2301 [email protected]<mailto:[email protected]> --- You are currently subscribed to tips as: [email protected]<mailto:[email protected]>. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13029.76c7c563b32ad9d8d09c72a2d17c90e1&n=T&l=tips&o=17089 (It may be necessary to cut and paste the above URL if the line is broken) or send a blank email to leave-17089-13029.76c7c563b32ad9d8d09c72a2d17c9...@fsulist.frostburg.edu<mailto:leave-17089-13029.76c7c563b32ad9d8d09c72a2d17c9...@fsulist.frostburg.edu> ________________________________ The information contained in this e-mail and any attachments thereto ("e-mail") is sent by Baker University ("BU") and is intended to be confidential and for the use of only the individual or entity named above. The information may be protected by federal and state privacy and disclosures acts or other legal rules. If the reader of this message is not the intended recipient, you are notified that retention, dissemination, distribution or copying of this e-mail is strictly prohibited. If you have received this e-mail in error please immediately notify Baker University by email reply and immediately and permanently delete this e-mail message and any attachments thereto. Thank you. --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=17090 or send a blank email to leave-17090-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
