The first project that I followed as statistician was the Bergen Hip Cohort Study (BHCS) a life-course investigations of growth process and health outcomes. Since September 2010, I have been working in the Millennium Cohort Study physical activity project for children aged 7 years. In June 2013, I joined the Life Study research group. As a member of the Life Study Methodology Scientific Working Group, I have contributed to methodological development and statistical input to the Life Study. In particular my activity was focused on the development and application of statistical technique which objective is to ensure representativeness of the Life Study’s findings, by attributing sample weights and dealing with missing data.