The Internet is a significant information resource for students due to the ease of access it allows to a vast amount of information. As the quality of the information on the Internet varies, it is important that students are able to evaluate such information critically. The aim of the study was to investigate how students evaluate Internet sources in an authentic learning task. Upper secondary school students (n = 25) were asked to look for source material on the Internet in order to write an essay. They were asked to verbalize their thoughts during the material gathering process. Their verbalizations and actions on the Internet were recorded and analyzed. The five evaluation profiles emerged: 1) versatile evaluators; 2) relevance-orientated evaluators; 3) limited evaluators; 4) disorientated readers; and 5) uncritical readers. (Contains 7 tables.)