Experimental Principles and Design In Psychology

vi;ill.;280hal.;23c

Curve matching using the fast marching method

Abstract. Common techniques for curve alignment find a solution in the form of a shortest network path by means of dynamic programming. In this paper we present an approach that employs Sethian’s Fast Marching Method to find the solution with sub-resolution accuracy and in consistence with the underlying continuous problem. We demonstrate how the method may be applied to compare closed curves, morph one curve into another, and compute curve averages. Our method is based on a local curve dissimilarity function F (t, s) that compares the two input curves C1(t) andC2(s) at given points t and s. Inourexperiments, we compare dissimilarity functions based on local curvature information and on shape contexts. We have tested the algorithm on a database of 110 sample curves by performing ”best matches ” experiments.

The Interactive Effects of Request Form and Speaker Status on Judgments of Requests

The interactive effects of request form and speaker status on judgments of requests were investigated in a laboratory study of metapragmatics. College students (N=132) read scenarios in which speakers made requests of them. Speakers were higher in status, peers, or lower in status than the subjects, and the requests were imperatives with semantic aggravators, embedded imperatives, or permission directives with semantic softeners. Subjects rated the speakers with respect to how rude/polite, humble/arrogant, and powerful/weak they were being. Significant interactions were obtained for the first two ratings, indicating that the speaker status effect was stronger with permission directives than with the other requests. These findings suggest that listeners view unexpectedly indirect requests as more impolite and sarcastic than requests used in other situations and, more generally, that language meaning is a function of both form and context