Internal and external validity in experimental economics: A review on the methodology. The aim of this study is to consider the methodology of the experimental economics. Economic research relies increasingly on experimental methods as a relatively new approach to collecting data in economics. Therefore, in this paper, we analyze and discuss the methodological foundations of experimental economics. The study starts with the elaboration on internal validity, followed by a general overview on external validity. In this context, the influence of experimental economics on the use of scientific methods in economic methodology and the dynamics of the trade-off between internal validity-external validity are discussed. The main result of the study is that it is more convenient to adopt a methodology compatible with aims and nature of each study instead of a standardized methodological approach, when the methodological dimensions of an experimental design are evaluated.