What is a quasi-experimental design?
A quasi-experimental design is one in which the researchers have only partial control over an independent variable. One or more of the variables cannot be randomly assigned.
Example: Gender, smoking, and depressin are all things that cannot be randomly assigned
What is a person-by-treatment quasi-experiment?
A person-by-treatment quasi-experiment is a design in which the researcher measures at least one independent variable and manipulated at least one other independent variable.
Example: A researcher finds people that are either depressed or non-depressed (measured variable) and for the study puts them in either a positive or negative mood (manipulated variable).
What is prescreening?
Prescreening is often done before the laboratory study in order to measure a large group of people on an individual-difference dimension (or attitude)
What is the difference between extreme groups and median split?
1. Extreme groups is when you take only the highest and lowest groups of people on a scale and throw out the middle
2. Median split is when you take only the ones in the middle and throw out the extremes.
What are natural experiments?
Natural experiments involve naturally occoring "manipulations." These often random life events were caused by facotrs that had nothing to do with the people who experienced them.
Example: Someone having their house destroyed by a natural disaster.
What is a nature-by-treatment study?
A nature-by-treatment study is one that combines natural events with laboratory manipulations, or that assesses individual differences among people and then waits for them to experience truly arbitrary natural events.
What is a patched-up design?
A patched-up design occurs when a researcher adds new conditions to a study to help establish the side of a quasi-experimental effect, to test for the influence of conceivable confounds, or both.
What are some of the threats to internal validity in designs that study one group before and after the quasi-independent variable?