Advisory services related to the phenomenon that all people, even very intelligent ones, tend to reduce the complexity of their problems to the level of the knowledge they happen to have. Since this happens unconsciously and since the result, the reduced problem, may lead to the pleasant feeling that one apparently is master of the problem, one is less inclined to give up this feeling. This leads to all kinds of strange behaviour, like not being able to listen to opinions conflicting with the remains of the problem. Examples: internet-hype; credit crisis. Google: 'tunnelvisie bestrijden', to find article, currently in Dutch.