The purpose of this qualitative phenomenological study was to explore how the post-adoption experiences of elementary school leaders influence their use of student achievement data in making educational decisions, after the implementation of a student information system (SIS). The participants consisted of K-5 elementary principals and assistant principals in a school district in the Mid-Atlantic region of the United States. It was not known how the post-adoption experiences of school leaders influence the way in which they utilize student data. This study was built on the constructs of the Technology Acceptance Model. The following research questions guided the study: How do school leaders explain and describe their experiences in using student achievement data in the post-adoption stage of a SIS? How do school leaders describe their experiences in using student data to make instructional decisions and to inform strategic planning? How has perceived ease of use and perceived usefulness influenced the experience of school leaders in the usage of student achievement data after the implementation of a SIS? The enhanced user experience, the usability and the usefulness of SIS were major themes that emerged from the data analyzed using a thematic analysis approach. Findings showed that school leaders' use of data was influenced by the lived experiences that they shared with the technology tool they use. The study provided vital implications that can assist school districts in developing the necessary infrastructure that will enhance data-driven decision making and increase student achievement. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]