PSY 121 Lecture Notes - Lecture 10: Random Assignment, Effect Size, Longitudinal Study
Document Summary
In order for experiments to have groups that are similar on key characteristics, must use random assignment. Procedure for assigning people to experimental & control groups in which each individual has the same probability as any other of being assigned to a given group. Experimenter effects: unintended changes in participants behaviour due to cues inadvertently given by experimenter. Experiments allow conclusions about cause & effect. Help to detect real effects and strong empirical evidence. Laboratory situations may be artificial (alternative of field research) Evaluating the findings: once data is collected, psychologists evaluate results in three ways, describe them, assess how reliable & meaningful they are, figure out how to explain them, accomplish this by descriptive & inferential statistics, and interpretation. Statistical procedures that organize and summarize research data (e. g. , graphs & charts) Statistical procedures that allow researchers to draw inferences about how statistically meaningful a study"s results are: most common are significance tests.
