| A | B |
|---|
| A-B-A | the baseline / treatment / baseline design used in single subject designs |
| ATTRITION | the loss of subjects over time |
| CONFOUNDING VARIABLE | an independent variable not manipulated, measured, controlled or randomized |
| CONTROL GROUP | the group which receives the placebo |
| DOUBLE BLIND | when neither the participants nor the researcher evaluating them knows which group has the treatment |
| FACTORIAL | a design looking at several independent variables is multi |
| INTERNAL VALIDITY | when there are few confounding variables, we may infer that the effects were produced by the manipulated independent variable |
| EXTERNAL VALIDITY | when the results of an experiment can be generalized across the population |
| JOHN HENRY EFFECT | when subjects in the control group are challenged to try harder |
| NOVELTY EFFECT | when subjects in the treatment group improve their performance because they are impressed with the newness of the treatment |
