This comprehensive and accessible book provides an overview of the central and most fundamental methodological issue for empirical researchers - how should we interpret statistical significance? Preface, A Litany of Criticisms of NHSTP, The Null-Hypothesis Significance-test Procedure (NHSTP), A Phenomenon and its Quartet of Hypotheses, Evidential Support for a Theory and NHSTP, Effect Size and Related Issues, A Critical Look at Statistical Power, Bayesianism, A Case for NHSTP, References, Author and Subject Index.