l with reference to industrial technique. There
we are still completely dependent upon certain experiences in the
field of experimental pedagogy, and upon certain statistics, for
instance, in the textile industry. Many patient investigations, with
every independent group of apparatus and machines, may be necessary
before psychotechnics will be able to supply industry with reliable
advice for teaching and learning. Nor have we the least right hastily
to carry over the results from one group of movements to another. Even
where superficially a certain similarity between the technical factors
exists, the psychophysical conditions may be essentially different. In
the two cases mentioned, for instance, telegraphing and typewriting,
the chief factor seems the same, as in both cases the aim is to make
the quickest possible finger movements for purposes of signals; and
yet it is not surprising that the development of the ability from the
beginnings to the highest mastery is rather unlike, as all the
movements in telegraphing are performed with the same finger, while
in typewriting the chief trait is the organization of groups from the
impulses to all ten fingers. At least it is certain that learning
always means far more than a mere facilitation of the movement by
mechanical repetition, and this is true of the simplest handling of
the tools in the workshop, of the movements at the machine in the
factory, and of the most complex performances at the subtlest
instruments. The chief factor in the development is always the
organization of the impulses by which the reactions which are at first
complicated become simplified, later mechanized, and finally
synthesized into a higher group which becomes subordinated to one
simple psychical impulse. The most reliable and psychophysically most
economic means for this organization will have to be studied in the
economic psychological laboratories of the future for every particular
technique. Then only can the enormous waste of psychical energy
resulting from haphazard methods be brought to an end.

A problem which is still too little considered in industrial life is
the mutual interference of acquired technical activities. If one
connected series of movements is well trained by practice, does it
become less firmly fixed, if another series is studied in which the
same beginning is connected with another path of discharge? I
approached this psychophysical question of learning by experiments
wh