This paper presents and discusses the following principles for planning, implementing, and evaluating World Wide Web-based lessons: (1) the roles of the teacher and students should be identified; (2) the nature of related contextual factors should be clarified before the planning session; (3) although the delivered content may differ in its degree of structural format, student participation should be exploratory rather than structured; (4) the teacher's attitudes should be supportive and open-ended; (5) in order to inspire learners to focus on the Web-based lessons and the related content, attractive multimedia and bizarre word expression may be frequently used, but not abused; (6) convergent or divergent techniques should be appropriately applied in the inquiry if the techniques are suitable for the nature of the subject matter; (7) ensure a good Web page design for Web-based lessons in order to promote effective learning by providing choices, saving time, retaining patience, and motivating automatic processes; and (8) alternative assessment is needed throughout each stage of planning, implementing, and evaluating of the teaching and learning process. (Contains 20 references.) (MES)