tory: Equipment and Utilization, in Trends in Language Teaching, ed. Albert Valdman (New York: McGraw Hill, 1966), pp. 215-33. 'Robert F. Mager, Preparing Instructional Objectives (Palo Alto, California: Fearon Publishers, 1962), p. 3. 6Harvey M. Taylor, Viable ESL/EFL Language Lab, TESOL Quarterly, 13 (1979), 229-39. 7'Joan Morley, Improving Aural Comprehension. Teacher's Book of Readings (Ann Arbor: University of Michigan Press, 1972), p. vii. John B. Carroll, Some Suggestions From a Psychologist, TESOL Quarterly, 8 (1973), 355-67; Judith O. Gary, Speak If You Don't Need To? The case for a listening approach to beginning foreign language learning, in Perspectives in Neurolinguistics and Psycholinguistics, ed. W. C. Ritchie (New York: Academic Press, 1978), pp. 185-99; Judith O. Gary & N. Gary, Comprehensionoriented Foreign Language Instruction-an Overview, The Linguistic Reporter, 23 (1980), 4-5; Stephen Second Language Acquisition and Second Language Learning (Oxford: Pergamon Press, 1981), especially Chapter 8; each chapter in this book had already appeared in article form in various journals. 9James J. Asher, Children's First Language As a Model for Second Language Learning, Modern Language Journal, 56 (1972), 133-39; Valerian A. Postovsky Effects of Delay in Oral Practice at the Beginning of Second Language Learning, Modern Language Journal, 58 (1974), 229-39. 'oSee Gary, Why Speak, for an overview. Krashen, p. 110. '2S. M. Ervin-Tripp, Structure and Process in Language Acquisition, in Georgetown University Round Table on Language and Linguistics, ed. J. E. Alatis (Washington: Georgetown University Press, 1970), pp. 313-53. 3E. H. Lenneberg, Understanding Language Without Ability to Speak: A Case Report, Journal of Abnormal and Social Psychology, 65 (1962), 419-25; Roger Brown, A First Language: The Early Stages (Cambridge: Harvard University Press, 1973). D. Van Lancker, Heterogeneity in Language and Speech, Diss. UCLA Department of Linguistics, 1972. Krashen, p. 83. '6Ibid., p. 83. '7Ibid., pp. 83-99. '8Ibid., p. 84. For an overview of experimental research on this topic see, for example, Chapters 6 and 7.