Online surveys are increasingly being used in empirical social research. They are cost-effective, can be conducted more quickly and with larger samples, and offer numerous quality advantages. Additionally, internet-based surveys simplify the integration of open and standardized questions, thereby allowing for the capture of motives, meanings, justifications, and subjective perspectives. These advantages also make them interesting for use in evaluations. Expensive transcriptions are eliminated, facilitating the implementation of mixed methods surveys. This book provides a detailed and practical introduction to the design, implementation, and analysis of online surveys using mixed methods. References to the evaluation standards of the Society for Evaluation help to enhance the quality of one's own evaluations.