Research Methods
Anecdotal evidence: Evidence gathered from others’ or one's own experience
Experiment: Scientific tool used to measure the effect of one variable on another
Independent Variable: Variable manipulated by the scientist
Dependent Variable: Variable being observed by the scientist
Within-Participants Design: Manipulating the independent variable within each
participant to minimize the effect of participant differences on the dependent
measure
Practice Effect
An improvement in performance over the course of an experiment as a result of
experience, separate from the effect of the independent variable
Confounding Variable
 A variable associated with an independent variable that obscures the effects
of the independent variable on the outcome
 This variable makes it difficult to draw findings and conclusions from an
experiment
Placebo Effect
The situation where an individual exhibits a response to a treatment that is not due to
its real therapeutic actions
Blinding
When participants do not know whether they belong to the experimental or control
group, or which treatment they are receiving
Experimenter Bias: Actions made by the experimenter, intentionally or not, that
influence the outcome of the experiment
Satistical significance: When the difference between 2 groups is due to some true
difference between the properties of the 2 groups and not simply due to random
variation.