Until now, there has been very little research into the use of online dictionaries. In contrast, the market for online dictionaries is increasing both for academic lexicography and for commercial lexicography, with sales figures for printed reference works in continual decline. This has led to a demand for reliable empirical information on how online dictionaries are actually being used and how they could be made more user-friendly. The volume Using Online Dictionaries makes a substantial contribution to closing this research gap. It is divided into four parts: The first part contains articles on fundamental issues: a research review of the empirical studies on digital dictionaries which have already been carried out, and a brief methodological guideline for lexicographical researchers who are interested in conducting their own empirical research. The second part contains the results of two studies that focus on general questions about the use of online dictionaries. It presents empirical data on contexts of dictionary use, on expectations and demands regarding online dictionaries. Furthermore, innovative features, such as the use of multimedia elements or the option of a user-adaptive interface and questions of design were assessed empirically. The third part of this volume comprises more specific studies of online dictionaries: an eye-tracking study evaluating the new web design of the dictionary portal OWID and a log file study which tries to get to the bottom of the following question: Do dictionary users look up frequent words, or put differently, is there a connection between how often a word is looked up and how often it appears in a corpus? In the last chapter of this thematic section, the question of how users judge the combination of a written paraphrase and an additional illustration in illustrated online dictionaries is addressed. The last part focuses on the use of monolingual dictionaries, in particular the German online dictionary elexiko. In this context, two online questionnaire-based studies were carried out. The empirical studies were conducted in the form of online surveys combining questionnaires and experimental elements and in the form of laboratory studies using eye-tracking technology as well as using observational methods such as log file analyses. Regarding the comprehensive research framework, this volume can be relevant to lexicographers, metalexicographers and linguists who are interested in the use of (online) dictionaries and in the development and exploration of lexicographical data for the internet, as well as linguists interested in empirical methods. It addresses a broad expert audience by presenting an academic subject which is currently the focus of much discussion.