Social facilitation: performance affected by presence of others. Obedience to authority: answer to how nazi germany happened. At least 39 witnesses to a 40 minute murder: no one intervened or even called the police. Assumed they were already called by other witnesses. Empirical design: correlational, quasi experimental, experimental. Hypothetico-deductive method: examine past knowledge / research, form a theory, operationalize the theory into a hypothesis, test hypothesis, revise theory. Independent variable: predictor, only implies causation when it is manipulated. Correlational design: two dependent variables, no experimental manipulation, random sampling, study. Exists a third variable co-occur: detect patterns as they happen in the real world i. e. not through lab experiments, statistical analysis. Quasi experimental: much like a correlational design, a defined predictor and outcome. E. g. sex / ethnicity / nationality: stratified random sampling, comparison / control group, study. Two age groups: age 3, age 5. Hu(cid:373)a(cid:374)s do(cid:374)(cid:859)t realize that people (cid:272)a(cid:374)(cid:859)t read (cid:373)i(cid:374)ds.