PSYC 3380 Lecture Notes - Lecture 2: Etch A Sketch, Dependent And Independent Variables, Political Gaffe

• School: University of Guelph
• Department: Psychology
• Course: PSYC 3380
• Professor: Jeffrey Spence

Document Summary

As psychologists we want to make claims about causality. X causes, predicts, affects, influences, explains, or is an antecedent of y . We can shy away from making causal claims and we can say: X is associated with y or that x is related to y . Recall the counterfactual model: trying to create equivalence in groups. If the experimenter uses random assignment, the individuals in the control and treatment groups are equivalent at the start of the experiment (theoretically interchangeable) so they represent each other"s counterfactual. Therefore, in the case of random assignment, the effect of the manipulation is simply the difference in y between the treatment and control condition. The change in y can stem from no other cause than that of the manipulation, hence causality. If internal validity is high, we are confident in causal claims. The degree to which we can draw conclusions about causal relationships in our data.