The study reported here had three major objectives: (1) assessment of average vocabulary and comprehension levels of Japanese college students studying English as a second language (ESL) and comparison of the effectiveness of several formats for teaching vocabulary, reading comprehension, and listening comprehension; (2) comparison of three media (traditional silent-reading, audiolingual methods in a language laboratory, and author-designed computer software in a computer laboratory) for teaching vocabulary and reading comprehension; and (3) gaining insights into second language teaching in general and ESL instruction in Japan in particular. Instructional materials were derived from one vocabulary workbook series. Subjects were first- through third-year students at six institutions in Japan. Results indicate that the intensive vocabulary training methods developed for the study were successful in teaching vocabulary usage and retention, with reading and listening comprehension improving as more vocabulary was mastered. Implications for classroom teaching and for future research are outlined. Extensive materials are appended. Contains 293 references. (MSE)