This report is an analysis of an investigation of staffing requirements for librarianship and information work carried out between 1972 and 1975 under the title of Sheffield Manpower Project. The results of the administration of a job descriptive questionnaire to members in a representative 45 per cent sample of libraries and information units (19 public, 47 academic, and 91 special libraries) in England and Wales are reported. The form of job description, covering the intellectual, social, and physical demands of the work environment, enables the personnel requirements for the jobs to be inferred fairly directly. An assessment is made of the degree to which existing personnel meet the demands of their jobs. The way in which library and information work is changing, and the roles of men and women, and of graduates are also discussed. Appendices include statistical data on the distribution of library and information units by type, size, and number of employees; job holders' biographical characteristics; and general identifying characteristics of jobs. Summaries of the best and worst features of library and information work, as reported by the sample population, and a classification of jobs by cluster analysis is also included. (Author/JPF)