1. AVOID FRUITLESS EXPERIMENTS 15 



keep informed may limit seriously the total research accomplish- 

 ments. 



2. Shun Negative Experiments 



Most investigators at one time or another have repeated experi- 

 ments previously reported by others, usually because it was felt that 

 the conclusions of the original experiments were incorrect. Occa- 

 sionally, however, the importance of a particular finding is such as to 

 render its earU^ confirmation highly advisable. Some investigators 

 hesitate to attempt any repetition of earlier experiments as a matter of 

 policy, feeling that a confirmation contributes nothing new and that 

 a contradiction cannot be reported unless it is based on an exhaustive 

 and extremely careful study. Since positive experimental results 

 normally carry much more weight than negative, a greater than usual 

 burden of proof is therefore placed upon the investigator who attempts 

 to establish negative results in opposition to a previously reported 

 positive finding. Nevertheless, it is very important to discredit 

 erroneous findings at the earliest opportunity. 



The repetition of an experiment for the express purpose of dis- 

 proving previously published results is not advisable unless a worker 

 is prepared to repeat the investigation in the painstaking and thorough 

 manner necessary to convince the skeptical. Serious thought should 

 be given in advance to the essential factors that constitute a satis- 

 factory negative experiment. On what critical points must the 

 eventual decision, regarding the facts to be accepted, be determined? 



In the history of science there have been a number of instances in 

 which established investigators in a field have failed to acknowledge 

 their own published mistakes. This constitutes a fault that is very 

 difficult to condone especially in a scientist. Since other workers are 

 prone to amass more and more evidence confirming the original mis- 

 take, the meanness of one man can thus lead to a great number of 

 otherwise needless and perhaps completely fruitless experiments. 



D. RECOGNIZE EXPERIMENTAL LIMITATIONS 



1. Theoretical Considerations 



All research methods are subject to certain limitations and the 

 realization of this fact can often result in a saving of experimental 

 effort that can then be directed into more profitable channels. These 



