These prescriptive WWW sites are functionally different from constructive sites. Prescriptive sites, both commercial and nonprofit, seek to present curricula, objectives, or other educational packages. They contain files that are designed and delivered as instructional tools. That is, they use the World Wide Web as a medium for the delivery of instruction itself, or to deliver prepackaged instructional material. Constructive Internet sites leave it up to the learner how to understand and use educational materials.
Constructive sites can be interactive sites where electronic tutoring takes place.
Other examples include virtual field trips, like guided tours of colonial sites such as Williamsburg or Jamestown, online museums, and hyperworlds. Based on the way prior knowledge shapes learning, instructional designers must be sensitive to the different knowledge bases of their intended audience. They must listen and watch, and be attentive to the learners as they use the materials. More specifically, the instruction was designed to help the students investigate the concepts of occupation, resistance, and sacrifice that are central to the plot of Number The Stars. Our needs analysis showed that students were lacking an empathetic understanding of what life was like for people who had endured hardships in the past.