The effects of learner control in Computer Based Instruction (CBI) were compared to learner control with advice as to what content to see next, and to programmed control. Students in training at the Basic Electricity/Electronics School, Service Command, Naval Training Center, San Diego, served as subjects in this study. Materials used were four lessons on using a multimeter. Students were assigned randomly to one of three treatment modes: learner control (student is free to choose individual lesson segments and content within lesson segments without restrictions on the order in which he sees individual materials or on how often he sees them); learner control with guidance (used an unobtrusive arrow superimposed on the lesson index or content choice page to recommend which lesson segment or lesson content the student should select next); or programmed control (imposed the same guidance parameters prescribed for the guided group but without choice). There was no significant difference in performance among the three groups. Following completion of the lessons, each student was asked to fill in an attitude questionnaire; there was no significant difference in the attitude towards CBI as a result of the different treatments. (VT)