Question

What are the advantages and disadvantages between a field and a lab experiment regarding both the internal and external validity?

Answer 1

Internal validity refers to the extent to which variations in the response or dependent variable are due to cause-effect relationship in independent and dependent variable.While the external validity is the extent to which the independent variable and dependent variable can be generalised to the population.

Field experiments are experiments performed in the field or the "real" world. Such experiments allow researchers to experiment without artificially introducing the confounding variables. The field experiments have high external or ecological validity or potential to adversely affect the behaviour of the subject under study. But they often lack a discrete control group and have a variety of variables which are difficult to eliminate, which might also question the internal validity of a study. These experiments have a higher levels of external validity

Lab experiments are experiments performed in a controlled or laboratory setup. These experiments have high internal validity as it is easier for the researcher to isolate the impact of other variables on the dependent variable. Whereas, lab experiments are done in a simulated environment where only a limited amount of variables are introduced/ manipulated by the researcher making it difficult to generalise the findings of the study to another population.