Two versions of a Web site on the United States Constitution were used by students in separate high school history classes to solve problems that emerged from four constitutional scenarios. One site contained embedded conceptual scaffolding devices in the form of textual annotations; the other did not. The results of our study demonstrated the situational importance of the annotations as well as the need for instructional Web designers to make their design intentions transparent. A holistic approach to examining annotational content is recommended in which teachers and designers consider how Web-based annotational content might function in instructional settings. An initial topology is also proposed for the annotations on the Web site used in this study.