The development and use of instruments for vocational guidance, selection, and placement within the State of Idaho are reviewed. Vocational guidance is defined as assisting the individual to understand himself, the world of work, and career choice. Selection and placement are described as activities characteristically used by educational institutions and business organizations in deciding who will be accepted and what roles and treatments would be expected of those who are accepted. Specific attention is given to research in which the General Aptitude Test Battery (GATB) was used to predict success in vocational training or work performance. Separate chapters are devoted to research studies with appraisal instruments completed in Idaho as well as 31 studies done elsewhere in the nation. Because more than three-fourths of the studies were completed as individual graduate research papers or theses, research results were generally not comparable or additive from one study to another. An extensive bibliography is included. An earlier study "A Survey of Literature Related to Selected Nonprofessional Occupations" is available as ED 013 915. (CH)