PSY 2174 Lecture Notes - Lecture 7: Internal Validity, Dependent And Independent Variables, Experiment

• School: University of Ottawa
• Department: Psychology
• Course: PSY 2174
• Professor: Yaroslav Konar

Document Summary

Goal of experimental research strategy: to establish existence of cause-and-effect relationship between 2 variables. Note that it"s possi(cid:271)le for (cid:1006) (cid:448)aria(cid:271)les to (cid:271)e related (cid:455)et relatio(cid:374)ship is (cid:272)oi(cid:374)(cid:272)ide(cid:374)tal (cid:894)e(cid:454) o(cid:374) pg (cid:1005)96(cid:895) True experiment: attempts to establish cause-and-effect relationship by demonstrating that changes in 1 variable are responsible for changes in another variable. Independent variable (iv): variable manipulated by researcher; typically by creating set of treatment conditions. Specific conditions used in experiment are called levels of iv. Dependent variable (dv): variable measured by researcher in all treatment conditions. Differentiating true experiment from other kinds of research studies: Research studies called experiment only if it satisfies st of requirements; for ex correlational studies are not. In natural setting, changes in 1 variable are accompanied by changes in other related variables (see ex pg 199) Problem w/ er: variables rarely exist in isolation. As a result, researchers are confronted w/ network of interrelated variables.