SOCPSY 2K03 Lecture Notes - Lecture 5: Random Assignment, Scientific Control, Internal Validity

• School: McMaster University
• Department: Social Psychology
• Course: SOCPSY 2K03
• Professor: Dr Glavin

Document Summary

Experiment: an operation or procedure carried out under controlled conditions in order to test a hypothesis. Used to examine cause-and-effect relations between an iv (stimulus) and dv. Involves manipulation of the iv to examine its effects on the dv, while holding constant extraneous variables (zs) Also involves random assignment of participants to various levels of the iv. Cepeda 2008, ran a series of experiments to examine impact of study intervals on test scores. Rq: is it better to review material over short period of time or spaced over longer period. Iv: length of time between 2 review sessions on test material. 1300 students randomly assigned to one of 2 groups. Hawthorne effect: term coined in reference to series of productivity studies at the hawthorne plant of western electric company in chicago, Researchers discovered their presence affected behavior of workers being studied. Term now refers to any impact of research on the subject of study research on the subject of study.