On 17 Apr 2011 at 9:44, Paul Brandon wrote: > I've seen Alex at work, and he was impressive. > For once, though, I agree with Dr. Sylvester; > Pepperberg's parrots never perform out of the sight of their trainers, > with the usual claims that the phenomenon is too fragile to be > manifested without the emotional support of the trainer. Red flag. > I'm still waiting for a systematic replication in an operant chamber.
I was surprised to hear Paul question Pepperberg's work by invoking the Clever Hans effect. I haven't looked into her work in any detail, but the fact that she publishes in respected journals led me to believe that she must have successfully dealt with this issue. In fact, it turns out she published an early paper on Alex in the Journal of the Experimental Analysis of Behavior, the holy book of operant conditioning. So if they felt it was kosher, can it be otherwise? The article is: Pepperberg, I. (1988). Comprehension of "absence" by an African grey parrot: learning with respect to questions of same/different. JEAB, 50, 553-564 and it's available for free at http://tinyurl.com/3j3jel3 She does deal with the issue in her methodology (see p. 558, right column), although she refers to an earlier paper for details, which I didn't chase down. It's apparently not strictly double-blind, but the primary trainer sits with her back to Alex, and is unaware of the stimuli being presented. Two students who did not participate in Alex's training do the testing. One selects the stimuli; the other presents them. I couldn't tell how well this protected against inadvertent cuing by the students but presumably she talks about this in the cited papers. Anyone know what the consensus is on this issue for Alex? Or should we just trust JEAB (than which none is purer) and its reviewers? Stephen -------------------------------------------- Stephen L. Black, Ph.D. Professor of Psychology, Emeritus Bishop's University Sherbrooke, Quebec, Canada e-mail: sblack at ubishops.ca --------------------------------------------- --- 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=10086 or send a blank email to leave-10086-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
