This collection of papers reports research on the effects of bilingual learning on the ability to speak two languages and the ability to acquire full literacy in both. There are 12 chapters in 4 parts. Part 1, "Background," includes (1) "Assessing the Effects of Bilingualism: A Background" (D. Kimbrough Oller and Barbara Zurer Pearson) and (2) "An Integrated Approach to Evaluating the Effects of Bilingualism in Miami School Children: The Study Design" (D. Kimbrough Oller and Rebecca E. Eilers). Part 2, "Overall Results on Language Use and Standardized Test Performance," includes (3) "Bilingualism and Cultural Assimilation in Miami Hispanic Children" (Rebecca E. Eilers, D. Kimbrough Oller, and Alan B. Cobo-Lewis); (4) "Effects of Bilingualism and Bilingual Education on Oral and Written English Skills: A Multifactor Study of Standardized Test Outcomes" (Alan B. Cobo-Lewis, Barbara Zurer Pearson, Rebecca E. Eilers, and Vivian C. Umbel); (5) "Effects of Bilingualism and Bilingual Education on Oral and Written Spanish Skills: A Multifactor Study of Standardized Test Outcomes" (Alan B. Cobo-Lewis, Barbara Zurer Pearson, Rebecca E. Eilers, and Vivian C. Umbel); and (6) "Interdependence of Spanish and English Knowledge in Language and Literacy among Bilingual Children" (Alan B. Cobo-Lewis, Barbara Zurer Pearson, Rebecca E. Eilers, and Vivian C. Umbel). Part 3, "Probe Studies on Complex Language Capabilities," includes (7) "Narrative Competence among Monolingual and Bilingual School Children in Miami" (Barbara Zurer Pearson); (8) "Command of the Mass/Count Distinction in Bilingual and Monolingual Children: An English Morphosyntactic Distinction" (Virginia C. Mueller Gathercole); (9) "Grammatical Gender in Bilingual and Monolingual Children: A Spanish Morphosyntactic Distinction" (Virginia C. Mueller Gathercole); (10) "Monolingual and Bilingual Acquisition: Learning Different Treatments of "that-trace" Phenomena in English and Spanish" (Virginia C. Mueller Gathercole); and (11) "The Ability of Bilingual and Monolingual Children to Perform Phonological Translation" (D. Kimbrough Oller and Alan B. Cobo-Lewis). Part 4, "A Retrospective View of the Research," includes (12) "Balancing Interpretations Regarding Effects of Bilingualism: Empirical Outcomes and Theoretical Possibilities" (D. Kimbrough Oller and Rebecca E. Eilers). (Contains approximately 280 references.) (SM)