This report presents results of a systematic analysis of an extensive database on study in the former Soviet Union assembled by the American Council of Teachers of Russian (ACTR) over a period of nearly 20 years. The purpose of the report is to document in detail the data used, the analytical strategy and methods employed, and most importantly the grounds on which substantive conclusions from the data rest. Three issues are emphasized: (1) interrelationships among preprogram language measures (standardized listening and reading proficiency tests, the Oral Proficiency Interview, and the grammar-based ACTR Qualifying Exams); (2) predictors of gain on various criteria, with particular focus on gender, knowledge of other languages, other individual attributes and characteristics of previous language learning careers, the Modern Language Aptitude Test, grammar-based ACTR qualifying exams, and proficiency in other language modalities; and (3) interrelationships among gains in different modalities. Data presented related to 658 students who studied in 4-month ACTR programs. Factors affecting gains are described (e.g., gender, age, and high school and college Russian). Analysis of residuals of gains indicates that gains on all modalities are positively interrelated, that gains in listening, reading, and oral proficiency tend to be associated, and that many students gain on one modality but not on the others. Seven figures and 25 tables are included. (JP)