Bauhaus-Universität Weimar

Experimental Psychology: A Manual of Laboratory Practice, Vol. II: Quantitative Experiments, part 2: Instructor's Manual
Titchener, Edward B.
The Metrie Methods 
Calculate Aru. Now set out from ru j| r,, and increase^; the series 
gives r"'u. Set out again from an rl noticeably and decrease r1 ; 
the series gives r""u. Calculate Ar'u. Average Aru with Ar’u to a final 
Ar. This is the DL of the stimulus ru. 
The only objections that the author can see to this procedure are : 
(i) that it tends to mask the fact that the DL is the j. n. increment (not 
decrement) of R ; (2) that it starts us upon our investigation without 
knowledge of our r, our point of final reference ; and (3) that it is un¬ 
necessarily cumbrous. The first objection is entirely, the second mainly 
pedagogical. The third raises the whole question of the advisability of 
the double procedure. 
It is clear that the double procedure cannot be applied, in this way, 
above r, for the determination of Ar0. The choice of rn as constant R 
in the third and fourth series involves an error, in so far as the Ar'"0 
and the Ar""0 must be referred roundly to r, instead of to that slightly 
different /?-value which (except by chance) will always form their real 
standard of reference. 
So far, we have been considering Wundt’s test-values as he has 
defined them, without seeking to penetrate more deeply than he 
has done into the psychology of the method. There can, however, 
be no doubt that the judgments of minimal changes are affected 
by factors akin to those discovered by Martin and Müller in their 
study of lifted weights by the method of constant ^-differences 
or r. and w. cases (Zur Analyse der Unterschiedsempfindlichkeit, 
1899). We return to this point in § 22, where we also con¬ 
tinue the history of the method by reference to Müller’s M. 
§ 21. The Method of Limits (Method of Minimal Changes) : 
Critical. —It is unnecessary to review here the criticisms passed 
upon the method of minimal changes, as minutely as we have re¬ 
viewed the development of the method itself. We have accepted 
a definition of the DL; we know something of the influence of 
type (i., I. M., xxv. ff.) ; we keep sharply distinct the measure¬ 
ment of magnitude and of precision of the DL. Moreover, as 
will appear presently, psychophysicists are beginning to get a 
clear idea of the interrelations of the four classical methods. It 
would, therefore, be waste of time to work over criticisms which 
show these definitions and distinctions in the making. We may 
confine ourselves to certain ‘ standard ’ criticisms, which still hold 
their place in the modern literature of the method.


Sehr geehrte Benutzer,

aufgrund der aktuellen Entwicklungen in der Webtechnologie, die im Goobi viewer verwendet wird, unterstützt die Software den von Ihnen verwendeten Browser nicht mehr.

Bitte benutzen Sie einen der folgenden Browser, um diese Seite korrekt darstellen zu können.

Vielen Dank für Ihr Verständnis.