Abstract

As the standardization study for the development of the norm for Korean Bayley Scales of Infant Development-II, 1,700 infants from Seoul and its vicinities, middle-, and south-regions of Korea were tested with the standardization version of the K-BSID-II. The test included two items developed through the pilot study and two newly developed items as well as extra two-six items from adjacent age group sets in addition to the original BSID-II. Korean infants showed a very similar Mental Developmental Index (M=99.71(SD=11.21)) to US counterparts but the Psychornotor Developmental Index (M=104.53 (SD=12.88)) was significantly higher than that of the US norm sample. The correlation between the MDI and PDI was very high (.99). There were high inter-scorer reliabilities for MDI(.91), PDI(.98), and BRS(.99). Gender difference was evidenced in both MDI and PDI at several age groups revealing the faster development among girls. There was also a significant regional difference revealing the highest performance among infants from the middle section. There were high reliabilities of BSID-II Behavior Rating Scale(BRS) in all age groups(.92-.96). There were some factors of BRS showing gender as well as regional differences. Validity as well reliability analyses will be followed.