A researcher conducted a true experiment testing whether a low-sugar diet versus a low-fat diet leads to a more substantial weight loss. If this experiment has high internal validity, what does it mean?
A) The participants did not know whether they were assigned to the low-sugar or low-fat diet.
B) The experiment was conducted in natural settings.
C) The experiment has established the effect of the diet type on weight-loss outcomes.
D) The results of the experiment can be generalized to the entire population.

Question

Quizplus · Accepted Answer

High internal validity means that the experiment has established a causal relationship between the independent variable (type of diet) and the dependent variable (weight loss outcomes) with minimal confounding variables. In this case, it means that the experiment has successfully shown whether a low-sugar or low-fat diet leads to more substantial weight loss. Options A and B are not necessarily related to high internal validity, and option D refers to external validity, which is not the focus of the question.

A Researcher Conducted a True Experiment Testing Whether a Low-Sugar