This article examines the merits of WebQuests in facilitating students' in-depth understanding of science concepts using the four principles of learning gathered from the National Research Council reports "How People Learn: Brain, Mind, Experience, and School" (1999) and the "How Students Learn: Science in the Classroom" (2005) as an analytic framework. Modifications needed to make a well-constructed WebQuests for science teaching aligned to the four principles include (1) integrating student science interests and cultural and social backgrounds to curricular goals and then using this as means to design WebQuests, (2) providing students opportunities to examine science-related Internet websites to discriminate credible and false information and then giving them the opportunity to include and use the websites for the "task" step in WebQuests, and (3) providing cognitive tools and guidance within the "process" step so that students are engaged in argumentation and negotiation akin to a community of scientists. (Contains 3 tables.)