To understand the value and impact of technology, it must be recognized that there have been three distinct phases in technology uses and expectations: Print Automation, Expansion of Learning Opportunities, and Data-Driven Virtual Learning. This report takes an in-depth look at these three phases and, for each, addresses two very important and highly interrelated questions facing educators as they try to determine the best use of technology in K-12 settings: (1) What evidence is there that the use of computer-based technology in each phase has a positive effect on learning? and (2) What significance do the findings from each phase have for educators today as they try to make technology-related decisions that have an impact on student learning? In Phase I, instruction was characterized by the use of behavioral-based branching software that relied heavily on drill and practice to teach segmented content and/or skills. During Phase II, computers become tools for learner-centered practices rather than content delivery systems, helping teachers move from largely isolated learning activities to applications that involved working in groups. Phase III carries with it the additional expectation of making schools more effective through the use of data-driven decision making of a much more sophisticated nature than previously expected. The conclusions of this report provide cumulative findings over the three phases, which are intended to help informed educators, policymakers, school administrators, school technical coordinators, and researchers make research-based decisions regarding the most beneficial approaches to technology use in K-12 education in the 21st century. (Contains 106 references.) (AEF)