The report, prepared to help the National Science Foundation determine the actions it should undertake to improve career guidance for future science majors, describes the current major theories and practices of career guidance; reviews career guidance materials in the sciences; summarizes what others are doing or contemplating; and recommends what should be done to develop effective and useful career guidance material in the sciences, including the information to be collected, delivery methods, and costs. Among the study's findings, obtained through surveys of secondary sources, visits to systems, State and Federal agencies, and interviewing and questionnairing of knowledgeable persons, are these: a lifelong career development model is replacing static conceptualizations of career choice; secondary students seem to desire various types of direct job experience; and two new practices consonant with developmental theories, career education and the computerized career guidance system, are emerging to supplement counselors' efforts. Thirty-three recommendations emphasize specific research needs and urge Foundation cooperation with other named agencies, particularly to improve the data base for a labor market information system. The recommendations reflect authorities' responses indicating that improving guidance materials and procedures for science students necessitates improving them for all. Appendixes include questionnaire returns, interview reports, and related documents. (AJ)