The objective of this half-day introductory tutorial is to increase awareness of what constitutes a sound scientific approach to evaluation in Visualization and to provide basic theoretical knowledge of, and practical skills in, current research practice of usability and evaluation. The content presents the current challenges and trends related to how to characterize and optimize the complex interactive visual displays present in Visualization today. It will cover the most basic and relevant issues to consider during different phases of evaluation: planning, design, execution, analysis of results and reporting. The content outlines how to proceed to achieve high quality results and point out common pitfalls and mistakes which are threats to high quality results. Taking part in this tutorial will not train a novice participant to be fully capable of designing and conducting an evaluation study and analyzing its outcome, such a goal would require a substantially larger course. The aim is to introduce the topic, provide general knowledge about what is important to consider and what resources are available to guide them in further study in this area. Further, participants will also learn to better judge the relevance and quality of a publication presenting an evaluation when reviewing such work since the same rules apply.