II. 



HISTORICAL SECTION 



The purposes of the present historical section are: i) To bring 

 together for critical consideration all the data reported up to the 

 present time on the rate of learning in successive association; 

 2) To present a brief critical review of the experimental litera- 

 ture upon the subject of simultaneous and successive presentation 

 in association; 3) To examine all data now published on the 

 strength of function of association in the backward as com- 

 pared to the forward direction; 4) To show that the evidence 

 is inconclusive because of its scantiness and, in some cases, its 

 general character. Due to the fact that in some of the experi- 

 ments reviewed more than one of the above-named issues is 

 discussed, it was deemed expedient to present the full report in 

 each case rather than to attempt presentation by topics. Crit- 

 icism and discussion have in some cases been deferred to the 

 Theoretical Section. 



Bigham 3 (1894) was among the first to investigate these 

 questions. For subjects he used five college students of an 

 average age of 24; for material, series of varied numbers and 

 colors (separate or in mixed series) mounted on cardboard 3J^ 

 cm. in size. Five simultaneous series were used and five suc- 

 cessive. In every respect the series were alike save in the manner 

 of presentation. The length of the series consisted of either 10 or 

 20 presentations. A 40 second period was allowed for each 

 series, 20 simultaneous presentations being made in this period, 

 and, in the successive series, two seconds being allowed for each 

 of the 20 cards. By this method the exposure time was two 

 seconds, whether the cards were presented simultaneously or in 

 succession. The subjects were asked to use no memory aids in 

 the learning. After a given series had had its due presentation 

 the subject immediately arranged his colors or numbers in the 



3 Bigham, ]., Psychol. Rev., 1894, Vol I, pp. 34-38. 



