*Accessible reference and text on a critical topic--testing pervades society, yet students find its core concepts challenging. *Class tested at two universities; the emphasis on conceptual understanding and application promotes critical thinking. *Flexible organization enables researchers and students to review the basics or delve into advanced concepts as needed. *Competing titles are pricey, dated, and not as reader friendly. *Examples and discussions walk readers through critical decisions in the selection, administration, scoring, interpretation, and development of measurement instruments.