Knowledge Bank

Children’s alphabet knowledge is among the strongest predictors of children’s early literacy skills (Scarborough, 1998) and is a key component of emergent literacy development (Whitehurst & Lonigan, 1998). Alphabet knowledge is typically conceptualized as total number of letters a child knows (i.e., a simple sum score). Therefore, the fact that some letters are more likely to be known than others (i.e., inter-letter differences) is not taken into account in alphabet knowledge assessments. However, research studies suggest that specific alphabet knowledge does vary in acquisition (McBride-Chang, 1999), indicating that researchers and educators should consider inter-letter differences in alphabet knowledge. In addition, some experts contend that there are potential inter-letter differences between upper and lower case letters. Sophisticated measurement techniques, such as those based on Item Response Theory (IRT), allow for a more nuanced and precise understanding of alphabet knowledge through explicitly modeling potential inter-letter differences. The purpose of the present study was to use IRT to further identify inter-letter patterns in children’s acquisition of alphabet knowledge, and thus provide insight for alphabetic assessment and instruction.