Knowledge, although seemingly available, is often not used for solving
problems, that means, it remains ''inert''. Three types of explanatio
ns for this phenomenon can be found in the literature. Meta-process ex
planations assume that the relevant knowledge is available, but it is
not used because of inadequate meta-processes (e.g., lacking metacogni
tive control). Structure deficit explanations suppose that the deficit
is rooted in the structure of the knowledge itself, that is, the know
ledge is not available in a form that allows for its application. In s
ituatedness explanations, the traditional concepts of knowledge and tr
ansfer are questioned. One basic assumption is that knowledge is funda
mentally situated, that is, context-bound. In recent years, instructio
nal models have been developed which try to remedy the inert knowledge
problem and which take into account many important aspects that have
been focussed in the different types of explanations referred to above
. However, in order to reach a sufficient understanding of the inert k
nowledge phenomenon, the cooperation of different psychological subdis
ciplines is called for.