This digest complements guidelines addressing the mechanics of online searching by considering how treating information searches as exercises in critical thinking can improve our use of online resources. It addresses the use and application of metacognition, hypothesis testing, and augmentation. Improving metacognition means improving the ability to monitor what we know and how we know it. Some ways to accomplish this include putting the project aside for a brief time, talking it out, and developing content knowledge. When these strategies have been exhausted, it is useful to find someone who may know more about it. Searching the literature should be an exercise in hypothesis testing, an exercise that can be improved by actively pursuing alternatives and taking an evaluative position. Once one adopts an evaluativist position, augmentation strategies help carry out the evaluation. Considering the structure and reliability of a source and remembering that even reputable sources are fallible are important. Using systematic analysis for a comprehensive, though time-consuming evaluation, is important. Heuristics are useful when it is necessary to make quick decisions, when there is not enough information for systematic analysis, or to complement systematic approaches. (Contains 11 references.) (SLD)