Students are increasingly using the World Wide Web (Web) as a science resource, especially to gather information on a variety of topics. The abundance of information on the Web makes it an especially tantalizing source of information, but not one without considerable risks due to its size and the inability of most Web search engines to organize and prioritize their search results. The purpose of this study was to examine searching patterns of students using the Web as a science information resource. We present cases of both successful and unsuccessful student experiences. Previous research demonstrates that domain knowledge and search expertise are particularly important in terms of students finding information on the Web. In light of these findings, we attempted to (a) provide detailed accounts of how students use the Web as a science resource, (b) illuminate how the different levels of domain knowledge, search expertise, and situational interest impact students' ability to find useful and relevant information on the Web, and (c) draw inferences about the types of tools and scaffolding needed by students when using the Web as a science resource. Detailed case descriptions of students' experiences facilitate discussion of how educators may integrate this popular information source more efficiently and effectively in their classrooms.