Growing Up in Ireland is a national longitudinal cohort study. The project started in 2006 and has followed two groups of Irish children, Cohort ’98 (formerly called the Child Cohort, most of whom were born in 1998) and Cohort ’08 (formerly called the Infant Cohort, most of whom were born in 2008). The principal aim of the project is to examine the factors which shape the development of children in contemporary Ireland and, through this, to contribute to the setting of responsive policies and to the design of services for children and their families.

This report describes the design and instrumentation on Growing Up in Ireland’s Cohort ’98 at age 17/18 years. The cohort members have reached age 18 or are approaching this age. This is an important milestone in the life of a young person as it reflects not just a new stage in the life course in terms of developmental maturity but is important in a broader societal context, with a range of civil rights and responsibilities conferred around this time. These include the right to vote, the right to work full time, and the right to consume alcohol.

This report is intended to provide a resource for researchers and policymakers to understand the rationale for, and background to, the measures included in the GUI study of 17/18 year olds. This chapter begins with a brief description of the background and objectives of Growing Up in Ireland. A summary of the conceptual framework underlying the project is also provided and this report documents how this framework is reflected in the instrumentation which was used when the young people at the centre of the study were 17/18 years of age.