For their usage in the semantic web valid ontologies are required for a given domain. Here we focus on ontologies represented as concept maps. We outline two methodological approaches for empirically validating concept maps. One procedure is to validate a given concept map with concept maps generated systematically by others. As a second method of validating a given concept map, we suggest to observe the behaviour in a relevant situational context as a validation criterion. In this scope, a method for predicting persons? problem solving behaviour by using a given concept map is outlined. In general, the purpose and ultimate use of a given concept map has to be taken into consideration for choosing a validation procedure and interpreting its results.