The purpose of this study was to investigate the effect of the structured inquiry powered by Web 2.0 technologies on remedying sixth-grade students’ alternative conceptions of “light” and improving their conceptual understanding. The sample of the study consisted of 16 sixth-grade students enrolled to a science course at a public secondary school. Since the study evaluated student gains in conceptual understanding by means of pretest and posttest scores, the study employed a single group pretest-posttest research design, with a conceptual understanding test (CUT) and semi-structured interviews employed as the data collection tools. The collected quantitative data was analyzed using IBM’s SPSS 15 statistical software, whilst the qualitative data was analyzed by way of content analysis. The analytical results showed that the structured inquiry powered by Web 2.0 technologies positively impacted the students' conceptual understanding of light, as evidenced by their ability to differentiate between different types of reflection and provide coherent explanations for light-related phenomena.