Identifying the identifiers: How iNaturalist facilitates collaborative, research-relevant data generation and why it matters for biodiversity science

The iNaturalist platform generates millions of research-grade biodiversity records via a system in which users collectively reach consensus on taxonomic identification. In the present article, we examine how identifiers and their efforts, an understudied component of the platform, support data generation. Identification is keeping pace with rapid growth of observations, assisted by a small subset of highly active users who tend to be taxonomically specialized. Identifier experience is the primary determinant of whether records reach research grade, and the time it takes to do so. Time to reach research grade has fallen rapidly with growing identification effort and use of computer vision, and research-grade identifications are generally stable. Most observations are vetted by experienced identifiers, although identifications are not free of biases. We close by providing suggestions for enhanced identification quality and continuing steps to enhance equitable credit and trust across the ecosystem of observers, identifiers, and data users.