Principal techniques and trends in the validation and analysis of data in magnetic fusion research are described and examples of applications are given. Wellestablished methods to obtain key physical quantities are outlined, as well as newer techniques employing integrated analysis of multiple diagnostics to improve quality and extract additional information from the data. Plasma control, confinement scaling, and transport studies, including model validation and development, are presented as important examples of applications of validated data. Finally, aspects essential to successful operation of future devices, which bring challenges due to a harsher environment for diagnostics, increased real-time requirements, and a geographically more distributed user community, are highlighted.