Having students inspect and use each other's work is a promising way to advance inquiry-based science learning. Research has nevertheless shown that additional guidance is needed for students to take full advantage of the work produced by their peers. The present study investigated whether scaffolding through an integrated support tool could bring about the desired effect. This tool was embedded in an online inquiry learning environment and outlined the steps in searching for information in peer-created concept maps. It also contained specific directions to assess the quality of the retrieved information. The effectiveness of this search guidance tool was investigated during an inquiry-based science project. Main results indicated that high school students who were supported by the tool (n?=?19) developed a more differentiated and interconnected conceptual understanding than students who did not receive this scaffold (n?=?23). However, the search guidance tool also seemed to put additional demands on students' self-regulatory abilities, and might therefore require some practice or regulatory support to reach its full potential.