The reader should be aware that this chapter is not a textbook in statistics or data analysis. It does provide an overview of some of the more common techniques used in data analysis, especially for data relationships. If the sensory professional is not trained in statistics, the help of a statistician should be sought in applying and interpreting many of the methods. Regardless of the training or experience of the sensory professional, it may be of value to combine forces with a statistician to obtain the maximum possible information from any study of data relationships as defined for this publication.