The purpose of this study was to identify, describe, and examine the perceptions of teachers and leaders when implementing a Web-based data warehouse (DW) for instructional decision-making in a K-12 public school setting. It identified the challenges and benefits of DW implementation by measuring teacher and leader concerns, studied teacher and leader perceptions of instructional uses of a DW, and described the levels of use of teachers to assess the progress of the implementation. It also identified areas requiring further attention and resources. The research questions that guided this study were: What are leader perceptions of use of a web-based data warehouse to make instructional decisions and what are teacher perceptions of use of a web-based data warehouse to make instructional decisions? Research sub-questions explored teacher and leader concerns with the implementation of a DW as well as expectations of instructional uses. A mixed-methods approach was used in the study. Two portions of The Concerns-Based Adoption Model (CBAM) were used to measure group concerns: the Stages of Concern Questionnaire (SOCQ) and the Innovation Configuration (IC). A 10 item survey was also administered. The findings from each of the three instruments were presented by research question. Concern profiles were established for each group, leaders and teachers. Levels of implementation and rates of agreement were analyzed and reported. Teacher and leader perceptions were compared. Implications and recommendations for educators described in this study include stopping resistance to change by providing identified resources and training and time for future collaboration and use. [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/en-US/products/dissertations/individuals.shtml.]