The approach of Statistical Methods in Education and Psychology, Third Edition, is conceptual rather than mathematical. The authors stress the understanding, applications, and interpretation of concepts rather than derivation and proof or hand-computation. Selection of topics in the book was guided by three considerations: (1) What are the most useful statistical methods?; (2) Which statistical methods are the most widely used in journals in the behavioral and social sciences?; and (3) Which statistical methods are fundamental to further study?