Environmental scanning, a part of strategic planning, begins with the collection of information from the broad social, economic, political, and technological climate surrounding an organization. The purpose of this study was to improve the guidelines for the first step in external environmental scanning by developing a checklist of suggested data public school personnel might consider. Through a modification of both Q-sort and Delphi techniques, 10 representatives of school districts across the nation who have experience in scanning (Practitioners) and 6 persons widely recognized for their contributions to the development of scanning literature and practice (Experts) scored the degree to which they would recommend 90 original test items and 4 items submitted by participants. Based on the final results, a suggested checklist of 68 items was constructed. Predictably, the majority of these 68 items concern population descriptions, budget patterns, socio-economic factors, and social issues. Most of the rejected items relate to housing, transportation, and economics. The same ten items scored highest in all three rounds. Nine of the items identify population size and composition or specific statistics on education enrollment and attainment. The tenth item was "number of single-parent families". No definitive explanation was reached as to why this issue was recommended over other equally popular and significant ones. Although consensus increased with each round, the group means continued to differ on 33 items. The disagreement in scores is most likely attributable to differences in perspective and in criteria used for recommending items. The study led to three major conclusions. First, the recommended checklist offers valuable assistance to scanners, especially novices, but it also has limitations. Scanners must adapt the checklist to their own situations and they must progress beyond any suggested list to explore new indicators of opportunities and threats. second, environmental scanning is still in the developmental stage even among experienced school systems. Finally, participant comments indicate a lack of rapport between Practitioners and Experts which could hamper efforts to adapt scanning to public schools. Despite these difficulties, continued implementation of external environmental scanning is strongly recommended.