In this study, six students were followed through 4 years of high school, documenting the impact of unlimited access to new learning tools--such as computers, scanners, and videodisc players--on their thinking, their approach to learning, and their interactions with others. The students were in two different classes and the years of case studies overlapped. After a total of 5 years of detailed observations of the students, as well as lengthy general and debriefing interviews, researchers saw dramatic shifts in students' thinking, learning, and interaction. The goal was to detail the extent to which students use the computer to expand their choices and ways of knowing, sharing, and collaborating. This study departs from most previous examinations of the impact of computers upon learning, in that traditional indices are not used to address the types of skills students acquire in high computer access classrooms. The focus is on computer literacy in terms of its symbolic, cognitive, and social dimensions. This study identifies eight student competencies or abilities: dynamic exploration and representation of information; experimentation and problem solving; social awareness and confidence; effective communication; computer use; independence; expertness and collaboration; and a positive orientation to the future. (Contains 5 references.) (Author/ALF)