PSYCH291 Lecture Notes - Lecture 18: Dependent And Independent Variables, Worst Behavior, Internal Validity
2 Jan 2017
School
Department
Course
Professor
Document Summary
Six special threats to internal validity to consider in pre/post. What are some alternate explanations for the observed changes in the dv: maturation, history, regression to the mean, attrition, testing. A change in behaviour that emerges naturally over time: ex. Interpretation (of relative effects of maturation vs. therapy. Therapy seems to accelerate the healing process. Treatment leads to a greater and faster decline in depression symptoms, with natural maturation. There is some decline in the grey lie too, (no treatment comparison group) which shows there is some maturation without therapy. A specific event (unrelated to the study) takes place between pre- and post-test and affects everyone in the group: unusual, outside event that effects everyone in your area, ex. Interpretation: energy consumption based on environmental campaign. In graph a, you (cid:272)a(cid:374)"t rule out histor(cid:455), histor(cid:455) is threate(cid:374)i(cid:374)g (cid:455)our i(cid:374)ter(cid:374)al (cid:448)alidit(cid:455), the go gree(cid:374) (cid:272)a(cid:373)paig(cid:374) did(cid:374)"t (cid:373)ake a(cid:374)(cid:455)o(cid:374)e (cid:272)ha(cid:374)ge their e(cid:374)erg(cid:455) use, (cid:374)othi(cid:374)g changed.
