It is up to the natural scientist and to him alone to define, in accordance with the procedural rules of his science, his observational field, and to determine the facts, data, and events within it which are relevant for his problems or scientific purpose at hand. Neither are those facts and events pre-selected, nor is the observational field pre-interpreted. The world of nature, as explored by the natural scientist, does not ‘mean’ anything to the molecules, atoms, and electrons therein. The observational field of the social scientist, however, namely the social reality, has a specific meaning and relevance structure for the human beings living, acting, and thinking therein. By a series of common-sense constructs they have pre-selected and pre-interpreted this world which they experience as the reality of their daily lives.1