In this video, we discuss the fourth and final major type of research design that psychological scientists use: experiments. We also discuss the limitations and other things to be aware of when conducting and evaluating an experiment.
Experiments: Research designs in which an experimenter manipulates a variable of interest to see if this manipulation impacts a second variable, allowing for cause-and-effect conclusions to be made.
Experimental Group: The group in an experiment that receives the key manipulation of interest.
Control Group: The group in an experiment that does not receive the key manipulation of interest.
Independent Variable: The variable that the researcher manipulates between groups.
Dependent Variable: The variable that the researcher expects the independent variable to have an effect on.
The Placebo Effect: Improvement resulting from the mere expectation of improvement.
Confounding Variables: Any variable that differs between the experimental and control groups other than the independent variable.
Experimenter Expectancy Effect: Phenomenon whereby experimenters’ hypotheses lead them to unintentionally bias the outcome of the study, known also as the Rosenthal Effect.
Double-Blind Study: Feature of an experiment in which neither the researchers nor the participants are aware of who is in the experimental vs. control groups.
