Abstract: <div class="abstract_container"> Most authoring tools for intelligent tutoring systems are targeted towards a broad range of applications. Such systems have expressive power but gain the complexity inherent in any general programming language. This paper considers a different kind of authoring tool, focused on creating content for a specific intelligent tutoring system. The resulting system, called pSAT, addresses the great demand for continuing development of content. A system like pSAT needs to be easily learned by end-users and needs to provide feedback adequate for the user to be able to determine that the system will correctly present the content under a wide range of user strategies, preferences and abilities. We focus on design principles driven by these considerations and conclude with a development strategy that begins with a closely-focused content authoring system and then broadens to a system that can more fundamentally affect the type of content presented by the intelligent tutoring system. </div> <p class="reviewers_container"> <strong>Reviewers:</strong> Chris DiGiano (SRI), Greg Kearsley (Nova Southeastern U.), Henry Lieberman (MIT) <div class="demo_container"> <strong>Interactive elements:</strong> <em>The Problem Situation Authoring Tool (pSAT) described in this article is available online.</em> </div> <div class="demo_container d2"> <strong>Demonstration:</strong> The Problem Situation Authoring Tool (pSAT) described in this article is available at <A HREF="http://domino.psy.cmu.edu:81/best/psat.html">http://domino.psy.cmu.edu:81/best/psat.html</A>. An online version of the Practical Algebra Tutor, PAT OnLine, is available at <A HREF="http://domino.psy.cmu.edu/patonline.html">http://domino.psy.cmu.edu/patonline.html</A>. </div>