The BONDS is aimed at generating knowledge about children's social, behavioral and academic development from age 6 months and onward. In the 15-year period from 2006 to 2021, eleven major waves of data collection from the children's parents were implemented, as well as additional data collections from child care centers and schools. The period covered the original study up to 4 years as well as two renewed consent periods: from 5 years through Grade 2, and from 2018 through 2021 when the three cohorts of children were in 5th to 9th grade. A flow chart shows participation, non-participation, and inactivity across data collection waves. Altogether 96.7% of the original 1159 participants were still participating at the end of the original study period at age 4: 85.9% in Grade 2 at the end of the first renewed consent period, and 43.3% in 2021 (Grades 7-9) at the end of the second renewed consent period.
Janson, H., Bringedal, G.E., & Nærde, A. (2023). A flowchart of participation and collected data across 15 years of the Behavior Outlook Norwegian Developmental Study (BONDS). Rapport. Oslo: NUBU. 2023 Report BONDS Participation.pdf
