NCDS Age 42 Sweep

Sweep details

Dates November 1999 to May 2000
Age 41-42
Achieved sample 11,419 (cohort members)
Respondents Cohort members
Fieldwork agency NatCen Social Research
Survey mode Face-to-face
Data access

Main dataset available via the UK Data Service [SN 5578]. Visit the UK Data Service website to access the data.


The age 42 sweep was the first conducted with a computer. The sweep was carried out in tandem with the BCS70 age 30 sweep and the majority of questions asked were common to both surveys.

A 75 minute interview asked about the following topics: household composition, housing, relationships, children, family life, employment, income, qualifications and training, health, smoking, drinking, use of illegal drugs, diet, leisure activities, exercise, values and attitudes, voting, social participation, skills and contact with police.

Special features at age 42

Contact with police/ use of drugs

The age 42 sweep collected information, for the first time, about lifetime and recent use of illegal drugs.

In addition, cohort members were also asked a series of questions about contact with the police and the legal system, including whether they had been arrested, given a caution or found guilty in court.

The inclusion of these measures allows researchers to examine early life predictors of drug taking and criminality, and the impact that involvement in these behaviours may have on other aspects of life.

Computer use

Questions about use of computers and the internet were first asked in the age 42 sweep and have been included ever since.

In recent decades computers and new technologies have transformed the way that we live. Home computers did not come into the mainstream until the 1980s when the NCDS cohort were in their 30s, and the internet did not become widely used until the late 90s when the cohort were in their 40s.

Adult learning and skills

NCDS is a key source of evidence on who is most likely to have low basic skills, and the wide ranging benefits of learning as an adult.

Much of what we learn at school prepares us for life as an adult – particularly basic skills like reading and maths. But some people reach adulthood with a poor grasp of literacy and numeracy.

The age 42 sweep included detailed questions about adult learning and skills. Researchers can use this information in combination with data from earlier sweeps to see how basic skills develop over time and to determine how literacy and numeracy are related to the other aspects of life such as employment, health, attitudes and relationships.


  • User guides
  • Questionnaires
  • Technical reports
  • Data notes
  • Additional
User guides

Handling missing data in the National Child Development Study – User Guide

This user guide aims to describe and illustrate a straightforward approach to missing data handling, while detailing some more general considerations around missing data along the way.

Date published: 12/07/2021
PDF: 657,33 KB


NCDS6/BCS 2000- Guide to the Combined Dataset

Date published: 01/06/2001
PDF: 1,2 MB


NCDS 2006 Re-deposit User Guide

User guide to accompany the redeposit of data up to age 46

Date published: 01/11/2006
PDF: 87,19 KB


NCDS Birth-Age 55 Response and Deaths Dataset User Guide

This document accompanies the deposit of the NCDS Response and Deaths dataset at the UK Data Service in March 2015.

Date published: 01/03/2015
PDF: 647,55 KB


NCDS Age 23-50 Partnership Histories

A guide to the partnership histories dataset collected from age 23 onwards

Date published: 01/11/2011
PDF: 245,98 KB


NCDS revised region variables

Date published: 01/03/2012
PDF: 523,56 KB


Partnership Histories Guide (1974-2013)

Date published: 01/11/2017
PDF: 374,82 KB


Activity Histories Guide (1974-2013)

Date published: 01/10/2016
PDF: 594,01 KB


NCDS Age 42 / BCS70 Age 30 Questionnaire

Questionnaire for cohort members administered for the NCDS age 42 and BCS70 Age 30 sweeps.

Date published: 01/12/2002
PDF: 3,15 MB


NCDS Age 42 / BCS70 Age 30 Questionnaire Appendices

Date published: 01/12/2002
PDF: 1,47 MB

Technical reports

NCDS Age 42 / BCS70 Age 30 Technical Report

Technical report on the NCDS age 42 and BCS70 Age 30 sweeps.

Date published: 01/09/2001
PDF: 1,21 MB


NCDS Age 42 / BCS70 Age 30 Technical Report: Appendices

Appendices for the technical report on the NCDS age 42 and BCS70 Age 30 sweeps.

Date published: 01/09/2001
PDF: 2,24 MB

Data notes

NCDS Age 42 Derivation of Hope-Goldthorpe Occupational Classification

This Data Note accompanies syntax devised to create a Hope-Goldthorpe scale classification of occupations for data from the 1958 National Child Development Study (NCDS) Sweep 6 (age 42)

Date published: 01/05/2007
PDF: 153,15 KB


NCDS Age 42 and BCS70 Age 30 Data Note 2: Pregnancy Histories

Assessment of combined pregnancy histories of BCS and NCDS when both surveys were conducted between 1999/2000

Date published: 01/12/2002
PDF: 436,93 KB


NCDS Age 42 and BCS70 Age 30 Data Note 3: Household Grid Variables

Assessment of combined household grid variables of BCS and NCDS when both surveys were conducted between 1999/2000

Date published: 01/12/2002
PDF: 592,55 KB


NCDS Age 33-42 Data Note 5: Partnership Histories

NB This publication has recently been superseded by the results of an exercise to distil employment data from NCDS4 onwards into one consolidated dataset. The dataset was deposited at the UK Data Archive in 2012, and is available for download. The user guide which accompanied that deposit are available from the User Guide section.

Date published: 01/05/2005
PDF: 97,75 KB


Deriving highest qualification in NCDS and BCS70

This Data Note explains the derivation of variables on Highest Educational Qualification obtained by cohort members in the National Child Development Study (NCDS) and the 1970 British Cohort Study (BCS70).

Date published: 01/01/2011
PDF: 514,11 KB


NCDS Birth-Age 50 Target and Achieved Samples

Table of target and actual sweep samples for NCDS up to age 50

Date published: 01/05/2008
PDF: 21,84 KB


NCDS Ethical Review and Consent

Review of the ethical practices throughout NCDS

Date published: 02/06/2014
PDF: 1,76 MB

Contact us

Centre for Longitudinal Studies
UCL Social Research Institute

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London WC1H 0AL