Question

​When participants in one treatment condition have characteristics that are different from the characteristics of participants in another treatment condition, then ____ may be threatened.

Answer 1

Answer:Internal validity

Explanation: Internal validity is a term used in research to describe how well experiments or researches are done, it is usually used to shows whether it avoids confounding, The less chance for confounding in a study, the higher its internal validity.

Internal validity tends to show the soundness of an experiment or research, it also shows how many Confounding variables you have in your experiment or research.