An experimental study of the Technology Immersion model involved comparisons between 21 middle schools that received laptops for each teacher and student, instructional and learning resources, professional development, and technical and pedagogical support, and 21 control schools. Using hierarchical linear modeling to analyze longitudinal survey and achievement data, the authors found that Technology Immersion had a positive effect on students' technology proficiency and the frequency of their technology-based class activities and small-group interactions. Disciplinary actions declined, but treatment students attended school somewhat less regularly than control students. There was no statistically significant immersion effect on students' reading or mathematics achievement, but the direction of predicted effects was consistently positive and was replicated across student cohorts. (Contains 6 tables and 1 figure.)