The early literacy development and its variability in children at risk of dyslexia: The prediction models of literacy deficits.

In the context of both projects Enhancing literacy development in European languages, work package 2 and The early literacy development and its variability in children at risk of specific learning disabilities, we monitored child development of literacy in preschool age and during the first years of school attendance in a four-stage process. The research group (n = 76) compound of typically developing children (BV = 37), children with the family risk of dyslexia (RR = 22) and children with specific language impairment (NVŘ = 17). We evaluated development of phonemic/phonological, lexical/semantic and morphological/syntactic skills, preliteracy skills and early literacy skills. The last fifth test stage included the assessment of literacy development in 3rd graders. First, a group of children with literacy deficits (n = 9) was identified via the latent profile analysis method. Subsequently, four predictive models of literacy deficits for each stage were created by means of lasso or L-1 penalized regression method. Predictive models follows the trend that until literacy skills are fully automatized (preschool age and the 1st grade), phonemic and phonological skills predominate, but later - after the formal learning to read and write proceeds - early literacy skills are becoming more and more..