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BCS70 – Child of CM (Multi-Age) – BAS Early Number Concepts

The 1970 British Cohort Study (BCS70) assessed the children of cohort members (CMs) during the study’s age 34 sweep using the Early Number Concepts measure from the British Ability Scales (BAS).

When the CM was aged 34, child assessments were conducted with the cohort member’s children. Each of the CM’s eligible children were asked to complete three exercises designed to measure a range of verbal and numerical abilities. Although dependent on the child’s age and abilities, each set of exercises was expected to take an average of 20 minutes to complete.

The BAS Early Number Concepts measure was administered as part of a set of ‘Early Years’ exercises (for children aged between 3 and 5 years and 11 months). Details on this measure and the data collected are outlined in the table below.


Year of data collection:2004
Domain:Pictorial reasoning
Measures:Verbal and visuo-spatial processing:
Knowledge of numerical and pre-numerical concepts
Verbal comprehension
Knowledge of basic language concepts
Visual perception and analysis of pictures
Integration of visual and conceptual information
CHC:Gf (Fluid ability)
CLOSER SourceNot currently available in CLOSER Discovery
Administrative method:Pointing or counting in response to plastic tiles and responses to colour pictures in a booklet. Recorded by interviewer on computer-assisted personal interview (CAPI)
Procedure:The child answered questions about number, size, or other numerical concepts. Stimuli used for the exercises included ten green plastic tiles and a series of pictures presented to the child, with 30 questions in total. A number of questions were asked for each of the pictures.
There were different starting and stopping points dependent upon age and performance. Starting and stopping points based on different ages and performance. These ‘rules’ were programmed into the computer to minimise the decisions interviewers had to make on the spot.
More details can be found in the user guide (in “Link to questionnaire” below) on page 8 and in Appendix A2.
Link to questionnaire:No link to the questionnaire, but user guide available: https://cls.ucl.ac.uk/wp-content/uploads/2017/07/BCS70-2004-Guide-to-Child-Assessments.pdf (opens in new tab)
Scoring:30 questions in total. Starting and stopping item depends on age and performance. Score 1=correct, 2=incorrect, except item 3 (counting tiles) which was scored 0 -6
Item-level variable(s):basenc01 - basenc30
Total score/derived variable(s):basencR (raw score)
basencA (ability and age adjusted)
Age of child (months):Mean = 53.95, SD = 10.56, Range = 36 - 71
Descriptives:basencR (raw score)basencA (ability and age adjusted)
N1,2261,226
Range0 - 2610 - 185
Mean15.33124.39
SD5.4126.47
(click image to enlarge)
(click image to enlarge)
Other sweep and/or cohort:None
Source:Elliott, C. D., Smith, P., & McCulloch, K. (1996). British Ability Scales Second Edition (BAS II). Administration and Scoring Manual. London: Nelson.
Elliott, C. D., Smith, P., & McCulloch, K. (1997). British Ability Scales Second Edition (BAS II). Technical Manual. London: Nelson.
Technical resources:Parsons, S., Bynner, J., & Foudouli, V. (2005). Measuring basic skills for longitudinal study: the design and development of instruments for use with cohort members in the age 34 follow-up in the 1970 British Cohort Study. NRDC: London. (Link opens in a new tab)
Parsons, S. (2006). British Cohort Study 2004 Follow up: Guide to Child Assessment Data, CLS Working Paper. (Link opens in a new tab)
Example articles:Cooksey, E., Joshi, H., & Verropoulou, G. (2009). Does mothers' employment affect children's development? Evidence from the children of the British 1970 Birth Cohort and the American NLSY79. Longitudinal and Life Course Studies, 1(1), 95-115.
Crawford, C., Goodman, A., & Joyce, R. (2011). Explaining the socio-economic gradient in child outcomes: the inter-generational transmission of cognitive skills. Longitudinal and Life Course Studies, 2(1), 77-93.
de Coulon, A., Meschi, E., & Vignoles, A. (2011). Parents' skills and children's cognitive and non-cognitive outcomes. Education Economics, 19(5), 451-474.
Mallows, D. (2013). The intergenerational transfer of numeracy skills. Institute of Education, University of London.

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This page is part of CLOSER’s ‘A guide to the cognitive measures in five British birth cohort studies’.