Internal validity is the extent to which an estimate identifies the intended effect within the population and setting actually studied.
Articles by others on the same topic
Internal validity refers to the extent to which a study accurately establishes a cause-and-effect relationship between the independent variable and the dependent variable, free from the influence of confounding variables or biases. In other words, it assesses whether the observed effects in a study can be attributed to the manipulations made by the researcher rather than to other extraneous factors.