José Luís Silva Araújo

Abstract The active participation of citizens in scientific research, through citizen science, has been proven successful. However, knowledge on the potential of citizen science within formal chemistry learning, at the conceptual and procedural levels, remains insufficiently explored. We developed a citizen science project - PVC: Perceiving the Value of Chemistry behind water and microplastics - which sought to involve students in monitoring the physicochemical parameters of coastal water quality, through the detection of microplastics in these waters, in addition to the qualitative identification of plastic contaminants on beaches. The project was conducted throughout the 2018/2019 school year and involved 442 middle school students (Key Stage 3 (KS3) aged 12-14, in Portuguese schools) and 9 chemistry teachers, in the northern coastal region of Portugal. The data on learning outcomes was collected through knowledge tests, applied after project conclusion, and was then compared to data collected up to six months later (retention test). In addition, interviews were conducted with participants, and researchers' field notes were recorded and analyzed. Data analysis suggests the PVC project promoted conceptual chemistry learning related to the analysis of physicochemical water parameters (pH, temperature, turbidity, salinity, nitrate and nitrite concentrations and dissolved oxygen), as well as polymers (polymer types, formation and structure). A positive knowledge retention was registered a few months after the project conclusion. At a process level, participants learned laboratory techniques (sieving, gravity and reduced pressure filtrations and crystallization) and the handling of laboratory materials. Furthermore, teachers recognized that their students' participation in the PVC project fostered the development of their argumentation skills, as well as their reflexive and critical thinking skills. The ability to communicate ideas and results, along with the development of students' digital skills, was also mentioned.

Abstract The promotion of positive attitudes towards science is an important goal of science education. This research aimed to identify students' attitudes towards science and whether their participation within a citizen science project has contributed to positive attitudinal changes. So, an attitudinal scale was developed, validated, and applied (as a pre and post-test) to 574 students aged between 12 and 14 years old. Positive attitudes towards science were recorded from the outset among children of both groups. Students' participation within the experimental group enhanced relevant positive attitudinal changes at the level of the critical analysis dimension, related to the perception of skills development such as questioning or critical thinking. Furthermore, positive attitudinal changes were achieved within the affinity dimension, related to perceived self-efficacy and appreciation of science and science classes. Positive attitudinal changes towards science among students indicate that citizen science contributes to enhance affective and attitudinal domains of their scientific literacy.

Abstract Contextualized and socially relevant hands-on activities are an effective way to promote students' involvement in the construction of knowledge. Considering the UN's 2030 Agenda for Sustainable Development, the preservation of water resources is crucial for the sustainable development of a country. Therefore, the PVC project was implemented in the context of water quality monitoring. There were 440 students and 9 chemistry teachers involved. A low-cost portable pedagogical kit was developed in order to determine the temperature, turbidity, pH, concentration of nitrates and nitrites, percentage of dissolved oxygen, salinity, and presence of microplastics in coastal water samples. The results indicate that the hands-on activities have contributed to the learning of chemical contents related to water quality parameters. Finally, the commitment, motivation, and autonomy of the participating students should be highlighted.