About 20 years ago the first empirical studies on the psycholinguistic structure of translation processes appeared. Based on data corpora, these studies investigated for the first time what goes on in the mind of translators while translating. Since then, process-oriented research in translation has developed into a research branch of its own within general translatology. The present article attempts to outline the fundamentals of this new branch of research by discussing four basic questions: (1) What are the characteristic features of process-oriented research in translation? (2) Which research questions is it designed to answer? (3) What methods are appropriate for collecting data relevant to the translation process? (4) What methods are appropriate for the systematic analysis and interpretation of the data collected?