This paper discusses the change process experienced by teachers participating in a study of a computer-based language arts instructional program for the early elementary grades--the Apple Learning Series: Early Language (ALS-EL). The study explored ways in which the teachers were implementing ALS-EL in their classrooms before attempting to determine whether the program was effective. Implementation 'quality' was measured by determining the extent to which teachers used a variety of ALS-EL software components, actively planned for curriculum integration, were familiar with all of the programs, made knowledgeable choices, and made appropriate use of hardware and peripherals including the sound synthesizer and printer. Results indicated that implementation quality varied widely across the six study sites, and that teachers' self-perceptions of their expertise with computers was highly correlated with their implementation quality. The roles of training, support, and leadership are discussed, as well as the ways in which a theoretical orientation to reading influences teachers' organization of instruction. It is argued that classroom design and management and, in particular, the teacher-learning relationship, are all factors that are affected by the teacher's prior experience and his or her general orientation to education. It is concluded that individual differences among teachers can make a substantial difference in the success or failure of implementing ALS-EL, and that time, resources, and support services are necessary for the successful implementation of innovative programs such as this. (24 references) (DB)