Bayley Test of Infant Development- 3rdEdition (Bayley-III)
The Bayley-III is a standardized measure to assess the cognitive, motor,
language, socio-emotional, and adaptive behaviors of infants and young
children between 1 and 42 months (Bayley, 2006). It is reported to have
high reliability (internal consistency among domains ranges between 0.83
and 0.93) and moderate validity (confirmatory factor analysis of domain
structure ranges between 0.50 and 0.79). We used the cognitive subtest
of Bayley-III to match the children between the DS and TD group based on
their cognitive developmental skills. The cognitive subtest assesses the
problem-solving, concept formation, and memory through tasks such as
completing puzzles, matching, and counting. The subtest raw scores can
be converted to scaled scores and age equivalents based on the scoring
norms. The age equivalents of the cognitive subtest were used to match
the children across the two groups (Table 1). One child with DS did not
complete the cognitive subtest due to non-compliance with the
experimenter during the session; their experimental data was included in
the final sample.