“For measuring response bias [in the 2AFC task], the methods [for the YN task] are entirely adequate. No sqrt(2) adjustment is necessary, because (as the reader may not be surprised to learn) bias in one task cannot be predicted from bias in the other.” Macmillan and Creelman, Detection Theory: A User’s Guide, 2nd Edition, p. 170. ------------------------------------------------------- Frederick (Erick) Gallun, PhD Associate Professor, Dept. of Otolaryngology, Oregon Health & Science University National Center for Rehabilitative Auditory Research Fax: 503-721-1402 http://www.ncrar.research.va.gov/AboutUs/Staff/Gallun.asp This document is intended for the exclusive use of the recipient(s) named above. It may contain sensitive information that is protected, privileged, or confidential, and should not be disseminated, distributed, or copied to persons not authorized to receive such information. Unless otherwise noted, this communication represents the views of the sender and not necessarily those of the VA or NCRAR. If you are not the intended recipient or feel you have received this document in error, please notify the sender immediately and destroy the original. From: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxxxxxxxxx] On Behalf Of Sam Mathias Dear list, I think I know the answer to this question, but I'd rather be totally sure. When calculating sensitivity (d') in a 2AFC experiment, one needs to apply the sqrt(2) correction to the standard YN equation. My question is whether the same correction needs to be applied when calculating the criterion (c) in 2AFC. Many thanks, -- 677 Beacon St., Boston, MA 02215 |