Growing Up in Ireland - the National Longitudinal Study of Children is a landmark study of children and youth which has been running since 2006. The objectives of the study are outlined in a separate publication (Greene et al. 2010). In summary the project seeks to further our understanding of what it means to be a child or young person growing up in modern Ireland, with a view to informing policy on what both helps and hinders development. A two cohort, cross-sequential longitudinal design was adopted and began with one cohort (Cohort 08) of 11,134 infants (aged 9 months) and a second cohort (Cohort 98) of 8,568 9-year-olds. A third cohort (Cohort 24) will follow infants from age 9 months. Being longitudinal in nature, the same children are followed over time. The families of Cohort 08 have been interviewed when the children were 9 months, 3 years, 5 years, 7/8 years, 9 years and subsequently at 13 years of age, while Cohort 98 and their parents/guardians were interviewed at 9, 13, 17/18 and 20 years of age. This dataset relates to Wave 5 of Cohort 98 when respondents were 25 years old.

Probability: Stratified: Proportional. GUI is a longitudinal study based on a fixed panel design. Cohort '98 follows the children and their families who were recruited into the study at 9 years of age for re-interview on several subsequent occasions. In the original design, the sampling frame was the register of primary schools in Ireland with a two-stage sampling design: a random sample of schools was selected from the frame, with a sample of nine-year old children then drawn from the selected schools. The design ensured that the sample was regionally representative and free from spatial bias. The 2006 Census of Population recorded 56,497 nine-year-olds in the country. The selected sample size of 8,568 accounted for approximately 14% of this population, equating to about 1 in every 7 nine-year-olds nationwide.

Face-to-face interview: CAPI/CAMI

Self-administered questionnaire: Web-based (CAWI)