The interest in the present work "school research conducted on the Web by primary and secondary school students" was driven by several concerns: What questions, purposes and guidelines do they have when using the Web for research? What paths do they travel on the Web? Do these paths aim at the construction or reproduction of knowledge? The general objective was to investigate how public school students research on the web, specifically, in the Portuguese Language subject. The research was a comparative study of cases to compare the intentional actions carried out by the subjects when they do content research on the web and their cognitive elaborations at different times of school years. For data collection, we used direct observation and semi-structured or unadjusted interview, when the researcher was guided by the observed actions. The research was on-site, where subjects made more use of the internet for school research. In the theoretical basis, precepts were used on school research as a process and everyday attitude with Demo (1994, 1996, 2000, 2001) and Padilha (2006); the purposes of reading with Solé (1998); reading on-line and browsing with Coscarelli (2014, 2016), and others. Through the observation and analysis of the two meetings with the GRAT participant, from the 9th year of elementary school, it was possible to reflect on how fragile and incomplete the understanding of the act of "researching" in the participant was inserted and the participant did not carry out a school search, but a query with literal reproduction. And, the RGSA participant, from the 3rd year of high school, showed a certain maturity and development, since it established initial questions, pursued research purposes and had autonomy for the daily attitude of the research. However, both GRAT and RGSA were not involved in school research as an ongoing, critical and constructive process to be mediated by the school in fulfillment of its role. This work is extremely important because its results will contribute significantly in the systematization of teaching practices for school research.