affect the outcome by non-consciously behaving in different ways to members of control and experimental groups. It is possible to eliminate the possibility of experimenter bias through the use of double-blind study designs, in which the experimenter is not aware of the condition to which a participant belongs. Mutual-internal-validity problem Experiments that have high internal validity can produce phenomena and results that have no relevance in real life, resulting in the mutual-internal-validity problem. It arises when researchers use experimental results to develop theories and then use those theories to design theory-testing experiments. This mutual feedback between experiments and theories can lead to theories that explain only phenomena and results in artificial laboratory settings but not in real life. See also All models are wrong Construct validity Content validity Ecological validity External validity Soundness Statistical conclusion validity Statistical model validation Validity in statistics References External links Internal validity (Social research methods) Causal inference Validity (statistics)