The development and use of a research tool to guide fourth-grade students' use of information sources during a research project is described in this article. Over a period of five weeks, 21 fourth-grade students in an international school in Singapore participated in a study investigating the extent to which the use of a "research resource guide" improved their independence in the research process. Findings indicate that students became more independent as a result of their use of the research guide. Students demonstrated greater consideration of a source's readability, trustworthiness, and usefulness when deciding whether to use it. The authors describe approaches to support students in making determinations about the readability, trustworthiness, and usefulness of sources of information. (Contains 8 figures.)