PSYC207 Lecture Notes - Lecture 9: Design Of Experiments, Covariance, Dependent And Independent Variables

• School: University of Delaware
• Department: Psychology
• Course: PSYC207
• Professor: Peter Mende-Siedlecki

Document Summary

Manipulation of variables: at least one manipulated and one measured variable, actively manipulate variables to randomly assign participants to conditions. Random assignment to condition: between-subject design: every participant has an equal chance of being assigned to any condition of the study, within-subject: every participant experiences every condition of the study (ideally in a random order) Experimental control: a particular comparison is isolated, while all other aspects of the situation are held constant. Independent manipulated; the cause; levels of an independent variable. Dependent variable (cid:373)easured; the (cid:862)out(cid:272)o(cid:373)e(cid:863); the effect. Controlled variables held constant across conditions. E(cid:454)a(cid:373)ple: size of a perso(cid:374)"s (cid:271)o(cid:449)l i(cid:374)flue(cid:374)(cid:272)i(cid:374)g ho(cid:449) (cid:373)u(cid:272)h people ate: What are the criteria for causality: covariance, temporal precedence. Change in independent variable is linked to change in dependent variable. Independent variable offers a mean of comparison by actively manipulating variable; establishes covariance. If x, then y (sufficient condition); if not x, then not y (necessary condition)