An overall rationale for the early identification of strengths and possible developmental weaknesses in school beginners is presented in Part I, with the research-based areas of assessment of tests for auditory analysis skills, conceptual skills and language skills. The general purposes of diagnostic assessment and a model of a behavioral assessment funnel for early identification and intervention are presented. The validity and reliability of the tests are discussed. Part II concerns each test's psychological and educational aim, physical characteristics and development. Administering procedures, research background and score interpretation are presented with implications for educators and parents. Part III is a theoretical and technical discussion of the underlying model of measurement in the series. The appendices include a technical glossary, a table of correlations and reliability coefficients, suggestions for intervention and remediation and a word source list for the word knowledge test. Tables for converting raw scores to ability estimates are given. Accompanying the handbook are test copies, directions for administration and score keys on: (1) word knowledge, (2) comprehension, (3) negation, (4) verb tense, (5) pronouns, (6) prepositions, (7) figure formation, (8) numbers, (9) recognition of initial consonant sounds and (10) auditory discrimination. (CM)