Data user guide

The Longitudinal Study of Australian Children: An Australian Government Initiative
Data User Guide – December 2018

2. What is LSAC?

Growing Up in Australia: The Longitudinal Study of Australian Children (LSAC) continues to examine the impact of Australia's unique social and cultural environment on the next generation.

The study tracks children's development and life course trajectories in today's economic, social and political environment. A major aim of the project is to identify policy opportunities for improving support for children and their families, and identifying the opportunities for early intervention.

The study investigates the effect of children's social, economic and cultural environments on their wellbeing over the life course.

2.1 Objectives

LSAC has a broad multi-disciplinary base and examines policy-relevant questions about development and wellbeing. The research questions span parenting, family relationships, education, child care, employment and health.

The study's longitudinal structure enables researchers to determine critical periods for providing services and welfare support, and to identify long-term consequences of policy innovations (for more details see LSAC Discussion Paper No.1, Introducing the Longitudinal Study of Australian Children).

The study is the first ever comprehensive, national Australian data collection on children as they grow up.

2.2 Who is involved?

LSAC is undertaken in partnership between the Department of Social Services (DSS), the Australian Institute of Family Studies (AIFS) and the Australian Bureau of Statistics (ABS), with advice provided by a consortium of leading researchers known as the LSAC Consortium Advisory Group (CAG).

The Wave 1 data collection was undertaken for AIFS by private social research companies: i.e., Colmar-Brunton Social Research and I-view/NCS Pearson. Data collection for Waves 2-7 was undertaken by ABS.

2.3 Timelines

Development for the study commenced in March 2002 with a testing phase involving over 500 families that continued through 2003. Recruitment for the main study took place between March and November 2004, and over 10,000 children and their families agreed to participate. From 2004, participating families have been interviewed every two years, and between-wave mail-out questionnaires were sent to families in 2005 (Wave 1.5), 2007 (Wave 2.5) and 2009 (Wave 3.5). Additional between-wave questionnaires (Waves 4.5 and 5.5) were undertaken via online web forms from 2009 for the purposes of updating the contact details of study participants. In 2015-16, B cohort study children were invited to participate - along with one of their parents - in a comprehensive clinic appointment or shorter home visit for a comprehensive, one-off physical health and biomarker module, known as the Child Health CheckPoint (between Waves 6 and 7).

2.4 Sample design

The focus of the study is on the developmental pathways of two cohorts of Australian children, so the study child is the sampling unit of interest. A dual cohort cross-sequential design was adopted as shown in Figure 1.

Figure 1: The dual cohort cross-sequential design of LSAC

Figure 1: The dual cohort cross-sequential design of LSAC

Two cohorts of children were selected from children born within two 12-month periods:

  • B cohort: children born March 2003-February 2004
  • K cohort: children born March 1999-February 2000

Further information about the design of the sample is available in the 'Survey methodology' section of this guide, and in LSAC Technical Paper No. 1, Sample Design [PDF 627 KB].

2.5 Study informants

The study collects data from multiple informants:

  • Study child is the cohort child.
  • Study child RAP (SC RAP) is the respondent who is living away from the parental home (in Wave 7 only applicable to K cohort children).
  • Parent 1 (P1) is defined as the parent who knows the study child best; in most cases this is the child's biological mother.
  • Parent 2 (P2) is Parent 1's partner or another adult in the home with a parental relationship to the study child; in most cases this is the biological father, but step-fathers are also common.
  • Parent living elsewhere (PLE) is a parent who does not live with the study child; most commonly the biological father after separating from the biological mother. This collection was started in Wave 2.
  • Teachers and child care workers involved with the study child.

In addition, LSAC data are linked to the file from the National Childcare Accreditation Council, Medicare Australia, ABS Census, the National Assessment Program - Literacy and Numeracy (NAPLAN), Australian Early Development Census (AEDC) and Centrelink.

2.6 Mother/Father data

While P1 is usually the mother and P2 is usually the father, this is not always the case. However, many users prefer to analyse the data by parent gender (i.e. mother and father rather than P1 and P2). Therefore, all the variables collected for both P1 and P2 are also presented as mother and father variables. Note that P1 and P2 may be the guardians of the child and not the child's biological parents. In this context, mother should be taken to mean 'female parent/guardian'. Sometimes P1 (and/or P2) might change between waves. For instance, P1 may be reported as female across subsequent waves, although the parent may, in fact, be different people.

If there are two female parents, P1 is coded as Mother and P2 is coded as Father. This will be maintained if the parents swap between P1 and P2 in subsequent waves. This means that there are a small number of female fathers that analysts should be mindful of when working with these variables. In addition, data users can use the sex variable to identify these if needed.

The majority of study child respondents live with their families. However in Wave 7 for the first time there were cases where the study child respondent lived outside the parental home. In these cases the study child respondent is defined as the study child respondent away from parents (RAP). The parents of the study child RAP are known as P1 RAP, P2 RAP and PLE RAP and their information is presented in main wave data files.