On Thu, 15 Feb 2001, Patrick Cabe wrote: > Jeff Ricker wrote, in part: > > In other words, the sum of the coincidences equals certainty. Plus, this > > all sounds like a case of "remember the hits, forget the misses." In > > science we have to consider the misses as well as the hits. > > ...and the false alarms and the correct rejections. This is one of those > classic 2x2 problems and one needs data in ALL FOUR CELLS to draw a conclusion. It's an interesting exercise to consider how to check the parrot out to debunk (ok, investigate) the claim. Here's a possibility. First, consider that precautions are in place to eliminate trickery and Clever Hansing (inadvertent cuing). Then the main problem is how to determine what a hit is (correspondence between parrot pronouncement and photograph), and whether the hit parade is better than chance. I'd let her owner choose all the photographs she likes. But I'd add an equal number of blanks, with no picture on them, and randomly distribute them among the pictures. Let the parrot blather about each from the other room, each photo (or blank) a trial. Here's the catch. Take the parrot's response to a blank, and randomly assign it to one of the photos. Then give the entire set--photos matched to utterance plus blanks randomly assigned to photos to utterance--to the owner to categorize as hits, without telling her which is which. If she can produce more hits for the parrotted photos compared with the randomly-assigned, she'll have a case. Of course, if the parrot is really psychic, it should start squawking "no fair!" each time a blank comes up. -Stephen ------------------------------------------------------------------------ Stephen Black, Ph.D. tel: (819) 822-9600 ext 2470 Department of Psychology fax: (819) 822-9661 Bishop's University e-mail: [EMAIL PROTECTED] Lennoxville, QC J1M 1Z7 Canada Department web page at http://www.ubishops.ca/ccc/div/soc/psy Check out TIPS listserv for teachers of psychology at: http://www.frostburg.edu/dept/psyc/southerly/tips/ ------------------------------------------------------------------------
