1372 
Experimental psychological investigation of children has been of 
still rarer occurrence with regard to the process of the concentration 
of attention in continued labour. Counterparts to the psychological 
investigations of children by von Voss’), Rivers and KRAEPELIN ®), 
AmbBerG*), WhryGanpt‘*) and other experimentalists of the München 
school, do not exist. They would not, indeed, have satisfied us in 
the form given to them by these authors. For, although the fluctu- 
ations manifesting themselves in different places of their activity- 
curve, whether they are due to the start, to accommodation, to 
practice, to fatigue, to the final spurt etc., are chiefly put down to 
the degree of attention, generally speaking, the task imposed upon 
the subjects was too complicate to bring out the effect of attention 
as clearly as possible. For this reason we have not made use of 
KRAEPELIN’S cipher-tests but of the cancellation-test. 
We need not enter into an argumentation about the well-grounded 
validity of Bourbon and Binet’s ®) crossing-test, applied in the inquiry 
into the process of a prolonged concentration of attention. It has an 
advantage over KRAEPELIN’s cipher-test in that, unlike this test, it 
does not put in requisition any other function except attention °). 
In a previous investigation one of us established the advantages 
of this test notably with regard to the attention in children ’). They 
consist above all in the fact that the test may be classed among the 
ordinary schooltasks, and that also young children take an interest 
in it provided they can read. Besides this, the experiment may be 
carried out, without any difficulty whatever, with several children 
simultaneously. 
The text consisted of a printed paper of 36 lines, comprising 
1768 letters distributed over 304 meaningless words. Some twenty 
1) Ueber die Schwankungen der geistigen Arbeitsleistung. Psychologische Arbeiten 
2, p. 399. 
*) Ueber Ermiidung und Erholung. Ibid. 1, p. 627. 
3) Ueber den Einfluss von Arbeitspausen auf die geistige Leistungsfähigkeit. 
Ibid. 1, p. 300. 
t) Ueber den Einfluss des Arbeitswechsels auf fortlaufende geistige Arbeit. 
Ibid. 2, p. 118. 
5) Attention et adaptation. L'année psychologique 6, blz. 364; B. Bourbon: 
Observations comparatives sur la reconnaissance, la discrimination et |l’association. 
Revue philosophique 40, p. 209. 
6) KRAEPELIN: Die Arbeitscurve. Philosophische Studien 19, blz. 459; vgl. ook 
E. Meumann: Vorlesungen zur Einführung in die experimentelle Pädagogik und 
ihre psychologischen Grundlagen III, Leipzig 1914, p. 390. 
1) F. Roers en Jon. WeRKER: Proeven over opmerkzaamheid bij doove, slecht- 
hoorende en normale kinderen. Tijdschrift voor Zielkunde en Opvoedingsleer 10, 
p. 209. 
