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ALSPAC – Age 7.5 – Letter Decision Task

The Avon Longitudinal Study of Parents and Children (ALSPAC) assessed their cohort members (CMs) during the study’s age 7.5 sweep (Focus@7) using the Letter Decision Task.

Details on this measure and the data collected from the CMs are outlined in the table below.


Years of data collection:1998-2000
Domain:Visual scanning
Measures:Visual scanning
Visual processing
CHC:Gs (Processing Speed)
Gv (Visual Processing)
CLOSER Source:Explore this sweep in CLOSER Discovery: ALSPAC Childhood (5 years to 12 years 11 months) (opens in a new tab)
Administration method:Trained interviewer; clinical setting; pen and paper
Procedure:The child was presented with a series of shapes, half of which were real letters, and half which were non-letters (including reversed letters). They were instructed to go through the list, placing a tick next to genuine letters and a cross next to non-letters. The speed of completion was recorded. This test was completed only by children who had struggled with other tasks, and thus the sample is considerably biased.
Link to questionnaire:http://www.bristol.ac.uk/alspac/researchers/our-data/clinical-measures/ (opens in new tab)
Scoring:The main score was the number of correct responses (0 - 40)
Item-level variable(s):Not readily available
Total score/derived variable(s):f7ws300 – f7ws348
Explore these variables in CLOSER Discovery: ALSPAC Focus at 7 Clinic Dataset (opens in a new tab)
Descriptives:N = 586
Range = 0 - 40
Mean = 34.19
SD = 5.71
(click image to enlarge)
Age of participants (months):Mean = 90.5 months, SD =3.83, Range = 82 - 113
Other sweep and/or cohort:None
Source:(Gathercole & Baddeley, 1997, personal communication)
Technical resources:None
Example articles:None

For the named items in the table above, links are provided to their corresponding content on CLOSER Discovery. Where a variable range is provided, full variable lists can be accessed through the ‘Variable Groups’ tab on the linked Discovery page.


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