BCS70 Age 34 Sweep

Sweep details

Dates February 2004 – June 2005
Age 34-35
Achieved sample 9,665 (cohort members)
Respondents Cohort members, cohort members' children
Fieldwork agency NatCen Social Research
Survey mode Face to face
Data access

Main dataset available via the UK Data Service [SN 5585]. Visit the UK Data Service website to access the data.


The Age 34 Sweep involved a 50-minute interview covering: relationships, births and pregnancies, lone parenthood, children, family life, housing, employment, income, qualifications and training, computer use, basic skills, physical and mental health, diet and exercise, alcohol consumption, smoking, height and weight, social participation, voting, attitudes, experience of crime, rating of local services and satisfaction with life.

Basic skills assessments measuring literacy and numeracy were administered, and a series of reading and writing exercises identified dyslexia symptoms.

For parents there were a number of additional elements:

Parent and Child Interview: an extension of the interview asking about each child’s health, separation from parents, pre-school care, education and aspirations for their future.

Parent paper self-completion questionnaires: age appropriate questionnaires about each child covering parenting, physical and cognitive development, parent/child relationship, behaviour, school absence and schoolwork.

Child assessments: Naming Vocabulary, Early Number Concepts and Copying Designs for those aged 3 to 5. Word Reading, Spelling and Number Skills for those aged 6 to 16.

Child self-completion questionnaire: Children aged 10 to 16 completed paper questionnaires about leisure activities, relationships with their parents, attitudes to school and aspirations for the future, self-esteem, smoking, drinking, drug use and experience of crime.

Special features at age 34

Basic skills assessments

Literacy and numeracy were assessed at age 34, as were symptoms of dyslexia.

Cohort members completed the same literacy and numeracy exercises they had taken at age 21, as well as questions extracted from the 2002 Skills for Life Survey.

The Government Skills for Life strategy was launched in 2001 and sought both to understand and tackle the problem of poor basic skills in a substantial minority of the adult population. Concerns were driven by the growing body of evidence that basic skills difficulties were a major impediment to successful functioning in modern society. As part of the Skills for Life strategy, the National Research and Development Centre for Adult Literacy and Numeracy (NRDC) was established, which funded the new questions to BCS70 cohort members at age 34. The data from these assessments provide an invaluable resource for the study of the antecedents and lifetime consequences of adult basic skill levels.

Parenting and children

Cohort members gave additional information about their children, and sons and daughters also took part in the sweep.

A randomly allocated 1 in 2 sample of cohort members completed an additional interview module and a paper self-completion questionnaire about each of their children. Cohort members’ children aged over 10 also completed their own questionnaires and a series of cognitive assessments, which allow for the study of transfer of ability from one generation to the next.


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

BCS70 Age 34 User Guide

User guide to the dataset for the age 34 sweep of BCS70

Date published: 22/04/2020
PDF: 1,33 MB


BCS70 Age 34 Adult Literacy and Numeracy Assessment Data

Assessment of Literacy and Numeracy data collected between ages 21 and 34

Date published: 01/08/2012
PDF: 2,3 MB


BCS70 Age 34 Guide to Child Paper Questionnaires

Guide to questionnaires administered based on child age and how they differ in design

Date published: 01/11/2006
PDF: 103,42 KB


BCS70 Age 34 Guide to Child Assessment Data

Guide to Child Assessment Data using the BAS II to allow for comparison opportunities to other cohort studies

Date published: 01/11/2006
PDF: 580,4 KB


BCS70 Partnership Histories (1986-2013) Guide

Date published: 01/10/2016
PDF: 370,43 KB


BCS70 Activity Histories (1986-2013) Guide

Date published: 01/07/2017
PDF: 660,51 KB


Handling missing data in the CLS cohort studies – 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: 03/06/2024
PDF: 1000,62 KB


BCS70 Age 34 Questionnaire

BCS 2004 CAPI questionnaire and report

Date published: 01/05/2004
PDF: 688,96 KB


BCS70 Age 34 Questionnaire Documentation

Formatted representation of CAPI Questionnaire for BCS Age 34 Sweep

Date published: 01/05/2005
PDF: 2,23 MB


BCS70 Age 34 Parent and Child Survey

Documentation for the BCS70 Age 34 Sweep Parent and Child Questionnaire

Date published: 01/05/2004
PDF: 237,68 KB


BCS70 Age 34 Questionnaire About Children Aged 0-11 Months

Questionnaire administered to parents with children aged between 0-11 months at the Age 34 Sweep of BCS70

Date published: 01/05/2004
PDF: 108,57 KB


BCS70 Age 34 Questionnaire about Children 1-2 years

Self-completion questionnaire for parents with children aged between 1-2 years and 11 months

Date published: 01/05/2004
PDF: 104,4 KB


BCS70 Age 34 Questionnaire about Children 3-5 years

Self-completion questionnaire for parents with children aged between 3-5 years and 11 months

Date published: 01/05/2004
PDF: 94,84 KB


BCS70 Age 34 Questionnaire about Children 6-16 years

Self-completion questionnaire for parents with children aged between 6-16 years

Date published: 01/05/2004
PDF: 98,38 KB


BCS70 Age 34 Questionnaire for young people aged 10-16 years

Self-completion questionnaire for children aged between 10 and 16 years

Date published: 01/05/2004
PDF: 119,67 KB

Technical reports

BCS70 Age 34 Technical Report- Appendix A

Various documents included with the BCS Age 34 Survey

Date published: 01/05/2005
PDF: 1,72 MB


BCS70 Age 34 Technical Report

Technical Report for age 34 of BCS70 (2004-2005 Survey)

Date published: 01/07/2007
PDF: 217,67 KB


BCS70 Age 34 Techinal Report- Appendix C

Outline of the coding and editing requirements for the BCS 2004 Study

Date published: 01/05/2005
PDF: 218,88 KB

Data notes

BCS70 Age 34 Assessment of Symptoms Associated with Dyslexia

The aim of the repost was to obtain a true estimate of the distribution of dyslexic symptoms in a representative adult population of 34-year-olds.

Date published: 01/09/2012
PDF: 205,97 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


BCS70 Revised Region Variables (Third Edition)

This User Guide accompanies the deposits at the UK Data Archive of derived variables for each sweep of BCS70. These derived variable datasets are found under the study number for each of the sweeps and include variables for country of interview, region and government office regions.

Date published: 01/02/2014
PDF: 307,78 KB


BCS70 Ethical Review and Consent

Review of Ethical procedures used for each Sweep of BCS70.

Date published: 01/01/2019
PDF: 4,18 MB

Contact us

Centre for Longitudinal Studies
UCL Social Research Institute

20 Bedford Way
London WC1H 0AL

Email: clsdata@ucl.ac.uk

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