Design used in experimental research in which groups are randomly formed and that controls most sources of invalidity is known as

True experimental design is a type of research design used in experimental research where groups are randomly formed and all sources of invalidity are controlled as much as possible.

Key PointsThis design involves manipulating an independent variable and measuring the effect on a dependent variable, while also controlling for extraneous variables that could influence the results.

In a true experimental design, participants are randomly assigned to different groups, including an experimental group that receives the treatment or intervention being studied and a control group that does not receive the treatment.

This random assignment helps to ensure that any observed differences between the two groups are due to the manipulation of the independent variable rather than other factors.

To control for invalidity, researchers may use various methods such as blinding, randomization, and controlling for extraneous variables.

For example, blinding involves keeping participants unaware of which group they are in to reduce the potential for bias, while controlling for extraneous variables involves ensuring that all groups are similar in all aspects except for the independent variable being manipulated.

Overall, true experimental design is a powerful tool for establishing cause-and-effect relationships in research, as it allows researchers to control for potential sources of invalidity and demonstrate that observed effects are due to the manipulation of the independent variable.

 Additional InformationQuasi-experimental design: a research design in which participants are not randomly assigned to groups.

Pre-experimental design: a research design that lacks a control group or randomization.

Ex-post-facto design: a type of research design used to investigate possible causes of a phenomenon that has already occurred.