4. Discussion and conclusion
The Internet is increasingly being used by students to complete school assignments (cf. Julien & Barker, 2009; Kingsley & Tancock, 2014; Mason et al., 2014; Van Strien et al., 2014). Because of the lowered threshold for publication of information on the Internet, students do not only have to understand the content during their learning process, but also to reflect about the validity of knowledge claims and with this about the credibility of Internet sources (e.g., Stadtler & Bromme, 2014). However, much research has shown that during Internet inquiry students spontaneously do not think critically about the sources from which they get their information (e.g., Kiili et al., 2008; Maggioni & Fox, 2009; Stadtler et al., 2014; Walraven et al., 2009; Wiley et al., 2009). Therefore, the primary goal of the present study was to test a paper-based worksheet intervention that prompts students during Internet inquiry to attend to and evaluate source information and to tag content for its source. Specifically, we tested the influence of such source prompts on the intertext model (i.e., readers’ mental representations of sources and source-to content links, cf. Britt & Rouet, 2012) that ninth-graders developed when reading multiple websites about an unsettled scientific issue. For this purpose, we provided half of the students with worksheets containing written prompts to fill in website names (cf. Britt & Aglinskas, 2002) and to classify the websites according to four given source categories (cf. Kammerer & Gerjets, 2012b). As in previous intervention studies that had found positive effects of source prompts (e.g., Britt & Aglinskas, 2002; Mason et al., 2014; Stadtler & Bromme, 2007, 2008; Wiley et al., 2009), the source prompts were presented during the learning process and were formulated specifically (cf. Bannert, 2009). The other half of the students worked with worksheets that did not contain such source prompts.
