Methodologies of social research offer considerable know-how about methods and techniques of empirical research in education. However, there is too little reflection on what we can and what we cannot know through empirical research in general and through the various research methods we use. This lecture attempts to clarify the epistemological premises of empirical research in education and of so-called “quantitative” and “qualitative” methods with a view to discussingthe opportunities and limitations of both paradigms in educational research. Researchers, so the primary concern of the lecture, should not only know the best ways to find out what they want to discover, but they also should reflect upon what they are not able to capture through the chosen methods. Methodologies of social research offer considerable know-how about methods and techniques of empirical research in education. However, there is too little reflection on what we can and what we cannot know through empirical research in general and through the various research methods we use. This lecture attempts to clarify the epistemological premises of empirical research in education and of so-called “quantitative” and “qualitative” methods with a view to discussing the opportunities and limitations of both paradigms in educational research. Researchers, so the primary concern of the lecture, should not only know the best ways to find out what they want to discover, but they also should reflect upon what they are not able to capture through the chosen methods.