In recent years the World Wide Web (WWW) has evolved into a major information resource enabling its users to comfortably and instantly retrieve an unprecedented amount of information on almost any topic. Besides searching for simple, unambiguous facts, people increasingly use the Web to research more complex and conflicting issues in critical domains such as health, politics, or finance (Fox, 2006; Rainie & Smith, 2009; Smith 2009). However, as anyone can publish virtually any information on the Web, the WWW is characterized by a large variability of information quality with information sources differing, for instance, with regard to Web authors’ expertise and motives. As a result, the trustworthiness of online information on topics like medicine or healthcare varies considerably, with many Web sites containing misleading or even false information (Bates, Romina, Ahmed, & Hopson, 2006). Therefore, the goal of our research has been to investigate under which preconditions and to what extent users engage in source evaluations, when searching the Web for conflicting medical or health-related issues. Our research includes studies with high-school students, university students, and nonacademic adults.