Many people spend a considerable amount of their time using media. Presence denotes the experience of being in this mediated environment--either alone or with some other (human) being, even when one is physically situated in another. In a similar vein, involvement denotes the intense processing of a mediated message or the personal relevance of that message. Which factors are important for these experiences, and which effects do they have? The present book aims at answering these questions. It gives a short and comprehensive overview of the concepts of presence and involvement. It discusses contributing factors and effects and also addresses methodological questions and concurrent approaches. The book is well-suited for students and researchers interested in the field.