For the psychologist, the objective of data analysis is to ascertain the existence and nature of relationships among variables (see Chapters Five through Seven). Generally, the focus is on parsimony, precision, and level of certainty. This chapter deals with aspects of data analysis and interpretation. However, since this book's central theme is conceptions and design, questions of statistics are kept to a minimum. Our coverage here must therefore be restricted in scope, a constraint that prevents our doing justice to a number of both obvious and subtle issues. Fortunately, these issues are fully covered in the abundant books on statistics and data analysis, from primers to advanced texts.