The study traced the assimilation of new administrative software in an Arab school, assisted by collaboration between the school and an Arab academic teacher-training college in Israel. The research used a mixed-method paradigm. A questionnaire consisting of 81 items was administered to 55 of the school's teachers in two stages to elicit their attitudes concerning the management of the assimilation process. To understand the teachers' perceptions, five of the questionnaire respondents were selected to participate in in-depth interviews. Quantitative data from the questionnaire showed that the teachers felt that the assimilation of the software had a positive influence on teaching-learning outcomes. They indicated that the change was important in comparison with the situation that had existed before the change. The factor that most predicted successful change assimilation was the teachers' positive perceptions toward change. The teachers' viewpoint on assimilation also correlated with the outcomes of the change after a year. Findings of the qualitative data from interviews showed that a process of inclusion in the college-school collaboration helped to motivate the teachers to assimilate the change . We conclude that the college-school collaboration was important for assimilation of change and the promotion of the school's effective teaching development.