This text is intended for advanced undergraduate- or graduate-level courses in statistics, experimental design, or analysis of variance found in departments of psychology, education and business or in schools of public health and medicine. Employing a single unifying theme throughout, and a model comparisons approach, the authors aim to give students a sense of how various design and statistical methods are interrelated, a sense of the "big picture" of statistics. Once students understand the underlying principles of this general approach and master a few basic formulas introduced early on, they should be able to view specific formulas for each individual design they encounter as a special case of more general formulas. They should be able to understand the logic that should guide their choice of a technique for a particular design.