Kj. Klauer, EVALUATION OF AN EVALUATION - COMMENT ON A REPORT BY HAGER AND HASSELHORN, Zeitschrift fur Entwicklungspsychologie und padagogische Psychologie, 25(4), 1993, pp. 322-327
The experiment of Hager und Hasselhorn (1993) is inconclusive. It is p
ossible that they did not have training effects at all because the gai
ns can be explained by retest effects. Moreover, it is possible that b
oth training programs have been effective in producing similar effects
because both fostered similar processes. The inconclusiveness of the
results could have been avoided by an appropriate experimental design.