Katagiri Hypothesis

3) Outline how Katagiri and his colleagues narrow (delimit) the scope of their review of the literature on autism spectrum disorder. How does this review assist the authors in the development of a cohesive rationale and testable hypothesis? Are the arguments persuasive regarding the purpose and importance of the research study? Why, or why not? Katagiri and his colleagues narrow the scope of their review of the literature on autism spectrum disorder by finding the problem in changing attention from a local level to a global level with two hypotheses. One hypothesis is the “weak coherence,” which “emphasizes the notion of reduced global integration of information” (Happe and Booth 2008). Another hypothesis is the “enhanced perceptual functioning,”

For example, to talk about print awareness influenced by genetic factor, the authors found a study from the International Longitudinal Twin Study, which explained, “a share environmental influence was roughly twice the magnitude of the genetic influence. Meanwhile, “a share environment influences on phonological awareness were found to be moderately low but nonetheless larger than the estimate of non-shared environment.” Therefore, the authors stated, “a multivariate approach is required to establish the degree of overlap in these etiological factors among the skills.” The perceived “gap” in the literature that the research wish to fill is whether the same genetic and environment factors are acting on the skills, such as the etiology of print awareness and phonological awareness and the etiology of decoding, from preschool to kindergarten during the phase when students initially read. The effectiveness of the arguments used different research to establish the rationale supporting the importance of the study about genetic and environmental influences on an early reader from preschool to