[gov3009-l] Gov 3009 February 19: Glickman

This week's speaker at the Gov 3009 seminar is Mark Glickman, speaking on "Combining Speed and Accuracy to Assess Error-free Cognitive Processes." The paper can be found at: http://math.bu.edu/people/mg/papers/spacc.ps, and an abstract follows. More information on the seminar can be found below. Abstract: Many experiments on human cognition involve having a subject make a judgment as quickly and accurately as possible. Both reaction times and error rates are widely used indices of human performance in such experiments. A difficulty in relying on either one of these indices alone is the problem of a speed/accuracy tradeoff; subjects who react quickly are more likely to have higher error rates, whereas subjects who are more accurate are likely to have slower reaction times. Another difficulty arises when subjects respond slowly and inaccurately (rather than quickly but inaccurately), e.g., due to a lapse of attention. We introduce an approach that combines response time and accuracy information that addresses both situations. The modeling framework assumes two latent competing processes. The first, the error-free process, always produces correct responses. The second, the residual process, results in all observed errors and some of the correct responses (but does so via non-specific processes, such as guessing in compliance with instructions to respond on each trial). Inferential summaries of the speed of the error-free process provide a principled assessment of cognitive performance reducing the influences of both fast and slow guesses. Likelihood analysis is discussed for the basic model and extensions. This is joint work with Jeremy Gray (Washington Univ in St. Louis), and Carlos Morales (Worcester Polytechnic Institute). Seminar Information: The seminar meets at noon in Room 22, Center for Basic Research in Social Sciences (CBRSS, 34 Kirkland St., this is the yellow building across the street from William James Hall). Contact information, previous presentations, and the spring schedule may be found at the course web site: http://www.courses.fas.harvard.edu/~gov3009/. Lunch is provided. To join the gov3009 mailing list, send e-mail to gov3009-l-request(a)fas.harvard.edu with the following text message: subscribe end Questions? Please contact the workshop coordinator, Liz Stuart, at stuart(a)stat.harvard.edu