THE STOP-WATCH AND THE ASSOCIATION TEST 



KNIGHT DUNLAP 



From the Psychological Laboratory of the Johns Hopkins University 



In performing the association test with groups of from three 

 to five " suspects," using a reliable chronoscope, I have never 

 had a failure, except from the attempt of some " innocent' ' 

 person to appear " guilty." In the cases to which I refer, an 

 assistant shows one member of the group a picture, or instructs 

 him to commit a simple act which is not known in detail to the 

 other " suspects;" then each in turn is put through a series of 

 free association reactions to twenty or twenty-five* words, con- 

 taining from five to eight words referring to the picture or act; 

 and from the response-words and the reaction-times, I determine 

 which is the " guilty" person. In these cases the method is 

 put to its severest test, because there is no strong desire on the 

 part of the "guilty" person to escape detection, and, as above 

 remarked, "innocent" persons sometim.es deliberately disobey in- 

 structions thus making their reactions appear "guilty." This 

 difficulty does not occur in real practice, hence its occurrence 

 in these cases does not constitute failure. In practical work, 

 given some details of the case which could be known only to 

 the guilty person; and a lively aversion on the guilty person's 

 part to being detected; there is small chance of failure with sus- 

 pects of average intelligence. 



It is true, nevertheless, that many experimenters report 

 failure in application of the method, and these failures re- 

 quire explanation. In some cases, undoubtedly, improperly pre- 

 pared word-lists are responsible: the preparation of the word- 

 list is the chief part of the test requiring skill. In other cases, 

 probably, the subject has not realized at the time of the test 

 that he was suspected. This realization is of course indispensable. 

 In still other cases it is possible that the technique of the reac- 



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