Chapter 2-2: Problems & solutions in research

Single-blind experiment
An experiment in which the participants are unaware of which participants received the treatment.
Double-blind experiment
An experiment in which neither the experimenter nor the participants know which participants received which treatment.
Control group
The group that does not receive the experimental treatment.
Placebo effect
Change in a participant's illness that results from a belief that the treatment will have an effect.
Self-fulfilling prophecy
A situation in which a researcher's expectations influence that person's own behavior, and thereby influence the participant's behavior.