a wide variety of terms is used to describe children whose school achievement is found to be deficient (e.g., school failure, learning difficulty, unerachievement, specific learning disability, dyslexia, and specific developmental disorder).”
(Hinshaw, 1992, p. 893)
“Recent evidence indicates that . . . . the patterns of differences between general and specific learning difficulties are less clear and less stable over time than once thought . . . . and sole consideration of children with specific learning problems neglects the very real achievement problems of children with IQ scores below the norm–children who are likely to suffer additional problems of low social class and poor educational opportunities. Furthermore, because the majority of children with poor achievement scores fall into the ‘general’ category, exclusive focus on specific learning disabilities limits representativeness. In short, the inclusionary criterion of an IQ-achievement disparity may unduly restrict sampling of achievement problems and may lead to neglect of important motivational and social factors that pertain to poor academic performance.”
(Hinshaw, 1992, 893-894)