Online community and citizen science (CCS) projects have broadened access to scientific research and enabled different forms of participation in biodiversity research; however, little is known about whether and how such opportunities are taken up by young people (aged 5-19). Furthermore, when they do participate, there is little research on whether their online activity makes a tangible contribution to scientific research. We addressed these knowledge gaps using quantitative analytical approaches and visualisations to investigate 249 youths' contributions to CCS on the iNaturalist platform, and the potential for the scientific use of their contributions. We found that nearly all the young volunteers' observations were 'verifiable' (included a photo, location, and date/time) and therefore potentially useful to biodiversity research. Furthermore, more than half were designated as 'Research Grade', with a community agreed-upon identification, making them more valuable and accessible to biodiversity science researchers. Our findings show that young volunteers with lasting participation on the platform and those aged 16-19 years are more likely to have a higher proportion of Research Grade observations than younger, or more ephemeral participants. This study enhances our understanding of young volunteers' contributions to biodiversity research, as well as the important role professional scientists and data users can play in helping verify youths' contributions to make them more accessible for biodiversity research.

Community and citizen science in online settings could be seen as a means for young people to engage with and contribute to authentic science. Yet, there is a limited understanding of who takes part in citizen science among young people, what they learn, and through which processes, particularly in online settings. In this exploratory study, we analysed 34 in-depth interviews and log files of young people aged 11-19 years old who took part in citizen science projects, hosted on the Zooniverse platform. Data analysis suggested that participation in online citizen science can bring environmental science learning benefits to young people, with some participants reporting evidence of agency with science, highlighted by taking action to do science in another context. Many participating youth exhibited substantial previous science experiences that helped them to take part and learn from citizen science projects. Considering findings from this study, we present a first working framework of how environmental science learning is enabled or hindered by certain types of participation, as a means to guide the design of online citizen science for young people. We recommend that the future project design, publicity and recruitment in online citizen science activities explicitly target the needs and interests of young people with diverse characteristics and competencies to truly open science to all.

BioBlitzes, typically one-day citizen science (CS) events, provide opportunities for the public to participate in data collection for research and conservation, potentially promoting deeper engagement with science. We observed 81 youth at 15 BioBlitzes in the U.S. and U.K., identifying five steps participants use to create a biological record (Exploring, Observing, Identifying, Documenting and Recording). We found 67 youth engaged in at least one of the steps, but seldom in all, with rare participation in Recording which is crucial for contributing data to CS. These findings suggest BioBlitzes should reduce barriers to Recording for youth to increase engagement with science.

We investigated youth participation in three Community and Citizen Science (CCS) programs led by natural history museums in out-of-school settings. Using second generation Activity Theory, we looked at repeated participation over time, collecting and then qualitatively analyzing ethnographic fieldnote observations on focal youth participation and components of the activity systems. We found each program provided multiple and unique access points for youth to participate in environmental science. Further, when facilitators emphasized the scientific goals of the programs clearly and repeatedly, youth participation in the scientific processes of the CCS programs deepened. Access to scientific tools, facilitation in using them, and repeatedly applying them in authentic research, enabled youth to participate in different aspects of CCS, from exploring to submitting biological data. Repeated participation in CCS activities provided the opportunities for youth to try the same type of participation multiple times (intensification), as well as provided the opportunity for youth to try different types of participation (diversification). Our findings suggest that repeated participation in authentic scientific research in CCS contexts fosters youth development of new roles and possible development of environmental science identities.