The Behavior of Noddy and Sooty Terns. 



249 



Table 3.- 



-Individual and average time-records of four sooties in learning Porter's 

 simple maze, in minutes and decimals of minutes. 



The error record is practically valueless because of the habits of the birds 

 and of the unsatisfactory' nature of the maze.^ 



The general features of the learning process are apparently not very 

 different from those obtained by Porter on the pigeons, English sparrow 

 and other birds. The time of the sooties, however, is markedly longer 



' I have been criticized both by Yerkes (Jour, of Phil., Psychol., and Scientific 

 Method, vol. iv. p. 585) and by Miss Washburn (Jr. Comp. Neurol, and Psychol., vol. 

 XVII, p. 532) for not presenting the error record in the case of the normal and 

 defective rats which learned the modified Hainpton Court maze (John B. Watson: 

 Kinesthetic and Organic Sensations : Their Role in the Reactions of the White Rat 

 to the Maze. Psy. Rev., Mon. Supp. No. 33). I wish to say in this connection that 

 mazes constructed along the lines of these two do not permit of a satisfactory error 

 record without an infinite amount of time being consiuned in the process. With the 

 above (Porter) maze a satisfactory error record w-ould have to be made on a basis 

 of the exact number of inches traversed in cul-de-sacs, the number of returns made, 

 the number of false turns made, etc. There would have to be some way of indicating 

 the value of a hesitancy at a blind alley, of a full turn into a blind alley, and the 

 difference in error value between traversing, say, S inches in an alley and going its 

 full length, etc. If one attempted to present an accurate record of the errors of a 

 test, one would consume several pages in the description of each of the first few trials. 

 If, on the other hand, one does not present such a descriptive record, and chooses 

 arbitrarily to call any random movement an error, giving all errors equal value, how- 

 ever much the random movements may differ in kind and extent, as Porter (op. cit., 

 p. 253) did in the case of the sparrows, pigeons, etc., and as Kinnaman (Am. Jr. Psy., 

 vol. 13, I, 173-218) did in tests on the monkeys, the record becomes valueless as a 

 basis of comparison with the work of others. Errors in this sense mean nothing 

 except possibly to the man who records them. Our technique in the field of animal 

 psychology is so crude at the present stage of the development of the science th.at the 

 problems which we present to our animals are not of the kind which easily permit the 

 recording of " errors." I shall welcome as eagerly as anyoiie a reconstruction of the 

 field in such a way as to permit such records. (Since writing the above I have suc- 

 ceeded in devising a satisfactory method for testing animals in the maze which per- 

 mits us to give both the time record of each trip and a record of the total distance 

 traversed by the animal at each trip.) 



