What is quasi experimental and give examples?

Quasi-experimental research design is a type of study that aims to evaluate the effects of an intervention without random assignment to treatment or control groups. This approach often uses existing groups or conditions, making it more practical in real-world settings. For example, a researcher might compare test scores between students in two different schools that adopted a new teaching method, or evaluate health outcomes in a community before and after implementing a public health campaign. While quasi-experimental designs can provide valuable insights, they are more susceptible to confounding variables than true experiments.