How do educators and instructional designers assess the effectiveness of the learning environments they design? One important means of ensuring the effectiveness of instruction in distance and face-to-face settings is through provision of learner support. Increasingly, as learners utilize the World Wide Web for collaborative learning, support systems contribute to the processes of learning and assist the learner in developing competencies and confidence in self-regulated learning and social interaction. Originating in the socio-cultural perspective of Vygotskyan theory, the term scaffolding refers to learning support based on social constructivist models of learning. As the World Wide Web becomes increasingly integrated into the delivery of learning experiences at primary, tertiary and secondary levels, the concept of scaffolding needs to be reconsidered because it is not readily translated into contexts where the teacher is not present, such as in online learning environments. The aim of this paper is to offer a conceptualization of the term scaffolding in distance learning, to provide examples of how learners can be supported in the processes of constructivist inquiry in a range of learning settings, and to offer principles for the design of learning support that can be applied across a range of instructional settings. (Contains 2 tables and 1 figure.)