Subject: Re: Dprime and false alarm rates From: Erick Gallun <gallun(at)BU.EDU> Date: Mon, 17 Nov 2003 13:58:13 -0500Pawel, Would you be willing to explain briefly what those measures are? I don't see how a reasonable statistic could account for a false alarm rate that reliably exceeds a hit rate unless the listener was using the wrong response label (i.e.- always calling the signal trials noise trials). I suggested to Kala off-list that her listeners may be at chance, thus producing occasional results where the FAs exceed the hits. I'm intrigued by your answer but would like a bit more info as I can't easily access some of those journals. Thanks! Erick Gallun Research Associate Hearing Research Center, Boston University At 03:55 PM 11/17/2003 +0100, Pawel Kusmierek wrote: >Kala Lakshminarayanan said: > > Has anyone had the > > problem of having false alarm rates that exceed the hit rate sometimes and > > not being able to calculate dprime? > >You may want to check the nonparametric sensitivity and responsivity >measures, such as SI and RI (Frey and Collier 1973 Learn Motiv 4:327) or >A' and B'' (Grier 1971 Psychol Bull 75:424, see also Stanislaw and Todorov >1999 Behav Res Meth Instr Comput 31:13). > >Pawel > > >-- >Pawel Kusmierek >Nencki Institute of Experimental Biology >ul. Pasteura 3 >02-093 Warsaw, Poland >phone: (+48 22) 659 85 71 ext. 388 or 379 >fax: (+48 22) 822 53 42 >email: p.kusmierek(at)nencki.gov.pl, pq(at)gazeta.pl