Personalization in computer-based systems aims at supporting users individually, by tailoring various system characteristics and components according to their respective needs and prerequisites. Traditionally, the emphasis hereby has most often been on either the content provided by the system, the way it is presented to the users or the way how users navigate through the system. However, additionally, the interaction process itself can be in the focus of a personalization approach. By personalized interaction processes, we subsume activities related to either efforts to personalize input on the user's side (e. g., through an individually tailored choice of input devices or their configuration), or a system's personalized output to a user (e. g., output modalities tailored to a user's abilities or preferences). In this chapter, we provide a concise overview of literature on personalized interaction processes and underlying user modeling activities and domains that have been in the focus of related research, and discuss the evolvement of this field throughout the past decades.