This diploma thesis presents an introduction into the fields of philosophy of science and epistemology of physics which are exemplarily being applied to modeling in cosmology.In a further step it suggests some approaches for the didactical realization of the issue.The emphasis is on facilitating a realistic estimation of natural sciences and their results regarding validity.Logic, the fundamental basis for thinking, and the most important historical stages in developing the modern natural science prepare the topic.Thereafter the procedural method to gaining knowledge in physics is worked out: Experiment, theory, consensus and dealing with inconsistencies. In doing so the character of contrariness, which is preeminent for the complex interplay of the named components, is pointed out.?Certainty?, respectively ?dependability?, as category of natural sciences distinguishes it from both the categories of the true and the formal accurate. Therewith a conceptual integration of the claim to reality and truth of natural scientific knowledge is possible.The theory of the ?Big Bang? and its critical analysis provide an insight into cosmological modelling which is discussed exemplarily from the viewpoint of the philosophy of science and epistemology.With regard to teaching about the nature of science in school the importance of intentionally confronting the students? views on the topic and their confrontation with real research is stressed. Therefore some motivating approaches in normal classes and in interdisciplinary, respectively, project class are being presented. This is, amongst others, done by means of the astounding but instructive example of the ?hollow Earth? hypothesis.