Population: the whole group of people you want to study
Sample: people that come to your study (from the population)
Random sampling: every individual from the population has an equal chance to be your sample
Ps/Ss: participants/subjects (=your sample)
Experimental control/manipulation: assign Ps to either control group or experimental group
Experimental/control condition = experimental/control group
Random assignment: every P has an equal chance to be assigned to the experimental group
Between-subject design: some Ps go to experimental condition, some Ps go to control
Within-subject design: all Ps are both experimental and control, repeatedly meaured
Independent variable (IV): the variable manipulated by the experimenter (IV is the only difference between the control group and the experimental group)
Dependent variable (DV): the variable measured as the study result
Null hypothesis: there is no difference in DV (after experimental manipulation) between the control group and the experimental group
Alternative hypothesis: there is a statistically significant difference in DV (after experimental manipulation) between the control group and the experimental group
Confounding variables: (1) might influence DV (2) eliminate it! (3) hard to totally eliminate (4) this is why we need random assignment (to minimize confounding variable's impact on DV)
Individual differences: (1) common confounding variable for between-subject design (2) can be eliminated/minimized by random assignment
Counterbalancing: to eliminate confounding variables in within-subject design
Operational definition: the procedure used to measure/determine the variables (e.g. ways to measure happiness)
Placebo effect: change in control group's DV that is not due to IV, but due to 'hope'
Demand characteristics: Ps often want to give/perform what (they think) the researchers want
Single-blind: to eliminate demand characteristics (by making Ps blind to their condition)
Experimenter bias: researchers (intentionally) vary treatment to two groups to get desired result
Double-blind: to eliminate (1) demand characteristics (2) experimenter bias *often in drug trials
Reliability: how dependably or consistently a test measures a characteristic
Validity : what characteristic the test measures and how well the test measures that characteristic
Self-Report Test: Personality Inventory, e.g. MMPI-2 (self-report bias or social desirability bias)
Direct Observation: Hawthorn Effect (workers being observed worker harder; observation changes the state of those being watched, which makes results obtained not entirely valid)