operational definition
Illusory Correlation The perception of a relationship where none exists. Placebo Effect Latin for "I shall please", Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.
A statement of the procedures (operations) used to define research variables. For example, human intelligence may be operationally defined as what an intelligence test measures.
scientific method
random assignment
A self-correcting process for asking questions and observing nature's answers.
A factor other than the independent variable that might produce an effect in an experiment.
placebo effect
hindsight bias
confounding variable
The tendency to believe, after learning an outcome, that one would have foreseen it (Also known as the I-knew-it-all-along phenomenon).
Assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to different groups.
