Can you give a brief example of a research study that is possibly effected by lack of internal validity by identifying a possible bias type?
An experiment that lacks internal validity is cause by the experimenter that did not control this variable. The main advantage of the experiment is that the experimenter can randomly assign treatment and remove all the confounding aspects. Internal validity is the ability to make causal conclusions. The huge advantage of randomized experiments over ...
This response explains how a lack of internal validity can affect a research study.