Quasi
A prefix meaning "almost"
What is "Quasi"
This type of experiment relies on naturally occurring events to study causal effects, without researcher manipulation.
What is "Natural Experiment"
Both quasi and natural experiments are used when this key feature of true experiments involving random assignment to groups is impossible.
What is random assignment?
This term describes a type of experiment where the assignment to treatment and control groups is not random.
What is a quasi-experiment?
In a natural experiment, researchers study the effects of events that happen without this, which is common in controlled experiments.
What is random assignment?
A study comparing two groups, one with a new treatment and one without, but without random assignment, is an example of this.
What is a quasi-experiment?
In quasi-experiments, researchers lack this key element of true experiments, which assigns participants to different groups.
What is random assignment?
In a natural experiment, the assignment to different conditions or groups happens due to this kind of event or circumstance, not by the researcher.
What is a naturally occurring event (or external event)?
In natural experiments, the independent variable is typically introduced by this rather than by the researcher’s design.
What is an external factor (or natural occurrence)?
Unlike true experiments, quasi-experiments may be used when random assignment is impossible due to these constraints.
What are ethical or practical constraints?
In a natural experiment, researchers observe a change's impact in the real world rather than in this setting, typically used in traditional experiments.
What is a controlled environment?
In a natural experiment, researchers often rely on this type of data, collected from real-world situations rather than a controlled environment.
What is observational data?
Quasi-experiments often compare these naturally occurring groups, which differ on the independent variable but were not randomly assigned.
What are pre-existing groups?
This type of study, where researchers don’t manipulate the variables but instead observe naturally occurring changes, is an example of a natural experiment.
What is an observational study?
This type of experimental design, including quasi and natural experiments, often lacks the tight control in laboratory settings.
What is a field experiment?