Science teachers are increasingly using internet sources for lesson planning, science content, and designing classroom activities. With the prevalence of disinformation online, there is potential for school students to learn ineffective internet search strategies and integrate disinformation into their knowledge. Science education fit for the future requires teachers who can navigate online information effectively and develop these capabilities in their students. In this study, we address the ways in which Australian preservice science teachers engage their cognitions about knowledge and knowing when searching and evaluating online information. Using concurrent think-aloud protocols we studied preservice science teachers' cognitions while completing internet search and evaluation tasks for science lesson content on socioscientific issues. Through subsequent interviews, we captured further dimensions of participants' knowledge and understanding of search and evaluation processes. We contribute new knowledge by providing a novel conceptual framework used for data analysis and empirical evidence about the cognitions (aims, value, ideals, and relied upon processes) that preservice science teachers engage when searching and evaluating online information. Implications for research and practice are discussed.