[111] SOME LIMITATIONS ON GENERALIZABILITY FROM SOCIAL PSYCHOLOGICAL EXPERIMENTS

The experimental model has severe limitations that often are ignored by experimenters. The limitations are likely to account for the low level of external validity of experiments. Placing the model in the context of requirements for measurement emphasizes the limitations and suggests alternatives for improvements in the future. hree major criticisms have been leveled at social psy-chological experiments in recent years. The first has raised questions about the ethics (APA, 1967) involved in: (a) the potential harm to human subjects and (b) deceiving subjects about the meaning of the experiment. The second is that experimental social psychologists too often have failed to realize that the experiment itself is a social occasion and that the results obtained may be due to subtle demand character-istics or to experimenter effects (Rosenthal, 1966; Rosenthal and Rosnow, 1969; Ome, 1962; Wuebben et al., 1974). Third, laboratory experiments have had little if any external validity. Two kinds of charges have been made concerning external validity. The first is that many experiments have little practical relevance, especially for the policy maker trying to utilize socia