The main purpose of this project was to discover favorable and unfavorable aspects of the 4-1-4 month calendar plan. The report contains information presented in tabular form obtained by questionnaire from 35 colleges and universities. An introduction and summary accompanies each of the 9 tables. Four of the tables summarize responses from 10 institutions currently using the plan. The cited advantages of the interim session include: reduced course load during the regular semesters, opportunities for independent study and off-campus study programs, the inter-disciplinary emphasis of course work, and the "change of pace." Disadvantages in this calendar arrangement include a loss of continuity in year-long courses, faculty load arrangement problems, poor student attendance, lack of student initiative, and the additional work required in planning. Some of the schools cited no disadvantages. Smith College, however, adopted the 4-1-4 plan, but dropped it because of compressed and rapid courses, weak projects, and lack of student initiative. The comments of respondents at 9 colleges that had not yet adopted the plan, but were either planning to, or interested in doing so, are also included. The questionnaire is included in the appendix. (DS)