Psychology 2800E Lecture Notes - Lecture 12: Experiment, Causal Inference, Repeated Measures Design

• School: Western University
• Department: Psychology
• Course: Psychology 2800E
• Professor: Patrick Brown

Document Summary

Characteristics of a true experiment: many activities may be called experiments which are not true experiments, let"s do an experiment! Independent variables and their levels: without these qualities, it is not a true experiment and you cannot detect cause-effect relations, manipulation, random assignment and control make the causal inference meaningful by setting up specific conditions. In within subjects (repeated measures) design, you do not need to randomly assign subjects to treatments because every subject gets the same treatment. Assignment of participants to treatments: two ways to assign participants, between groups each participant gets only one level of a treatment, within subjects each participant gets all levels of a treatment. Some are motivated, some aren"t, some have good vision and some don"t etc. If there is no treatment effect, the ratio becomes error variability/error variability, and should be roughly equal to 1. 0.