Scenario G

In a study of the effects of vitamin A on maze-learning ability of rats in a semi- darkened environment, a researcher had reason to believe that enhanced performance would occur under minimum dosages but that at higher dosages performance would decrease. The experimenter selected four levels of vitamin A ingestion. The highest level had been shown by previous research to be toxic to rats, but the researcher argued that to demonstrate the hypothesized results such levels were necessary.

Previous research had also suggested that higher levels of vitamin A interfere with maze performance, but the hypothesis had not been tested empirically. Thus, the results would reveal something new and would have important scientific implications.

The rats were well cared for except for the high level of vitamin A ingestion in one group. Upon collecting the minimum amount of data necessary for analysis, the experiment was terminated and the rats were rapidly and painlessly killed.