I. AVOID FRUITLESS EXPERIMENTS 9 



nature of experimental data demands that some appropriate interval 

 of time be chosen as a guide in making observations. The value of 

 this interval must be determined by the nature of the problem itself. 



In making observations, the scientist selects some of the facts for 

 attention; he does not attempt to record all of them. Scientific facts 

 represent relatively only a very small number of all the facts that 

 could be observed. Although scientists deliberately choose certain 

 facts for observation, the selection must be made on the basis of proper 

 criteria and in an impartial manner according to the unwritten code 

 called scientific honesty. The choice is not one of mere caprice nor can 

 it be purely arbitrary in order that the facts may fit into some pre- 

 conceived scheme. To be accepted as fact, experiments must be re- 

 producible by others. 



The ability to distinguish readily the critical factual items in an 

 experimental situation is the mark of a capable scientist. Although 

 good scientists must be opportunists in the sense of making the most 

 of unexpected observations, they must also simulate bloodhounds and 

 not be distracted constantly by irrelevant facts of an inconsequential 

 nature. 



3. Discard Meaningless Questions 



Scientific experiments are undertaken in order to answer questions 

 concerning nature. To state that an experiment is meaningless 

 either implies failure in securing an unequivocal or satisfying answer 

 to the question, or it suggests that the question itself is without 

 meaning. In a philosophical sense, one can defend the thesis that 

 seriously propounded questions concerning nature always possess 

 meaning. Only when a specific point of view is adopted does it become 

 possible to define questions as meaningless or to assign a scale of 

 values to them. One such point of view has been expounded by 

 Bridgman (1, p. 28), who classifies questions as meaningless unless 

 they can be answered by means of ''operations." For instance, it 

 means nothing to ask whether a star is at rest or not. To laboratory 

 workers, "operations" connote experimental manipulation and ob- 

 servation. From this standpoint, for example, the question of whether 

 there was once a time when matter did not exist possesses no meaning. 

 Presumably in the same category is the question whether a rabbit and 

 a mouse experience identical sensations to the color red. But all 

 questions that could be answered in terms of operations would be 

 meaningful. 



