When in the "zone of proximal development" for a particular skill or piece of information, a learner is ready to learn but lacks certain prerequisites. Scaffolding is an interactive process in which a teacher or facilitator assists such a learner to build a "structure" to contain and frame the new information. Scaffolding can be provided by teachers, peers, or computers, and may include the use of tutoring, performance systems, and reciprocal teaching. Online scaffolding practices include scaffolding embedded in the information, such as visual cuing, separate web pages of directions on what to notice or what process to employ, tutorials that are interactive or downloadable, help pages, additional explanatory links, or communication forms to contact the instructor or peers. In computer-mediated learning, scaffolding is more important than in traditional education because learning is typically collaborative, and all participants will provide scaffolding to other participants at different times during the learning process. Therefore, participants must be exposed to the idea of scaffolding and know when it is appropriate in the dialogic process. Pointers on appropriate use of scaffolding are given. The teacher may have to provide prerequisite skills to some students. A computer environment makes the provision of these easier because there is much prepackaged material on the Internet, including visuals, illustrations, and simulations. Students can create materials to help less sophisticated students, and post these on the class web page, thus creating a learning archive. The four stages of facilitated learning, from a constructivist view, are described, as is coaching in collaborative computer-mediated learning. The measure of a well functioning group is the decreasing need for external scaffolding from the teacher, as the members scaffold each other. Contains web sites for online resources. (TD)