Over the past few decades a considerable amount of research has been devoted to the search for factors that may affect or predict the development of reading and spelling abilities. Instead of looking for factors in the child's environment that may lead to differences in the mastery of literacy skills, cognitive psychologists have directed their investigation to differences in cognitive processes that are intrinsic to the child (Snowling, 1995). This approach has been proved particularly fruitful, and a number of cognitive and linguistic measures have been proposed as possible predictors of literacy skills, including measures of phonological awareness, verbal STM, rapid naming, speech rate, or syntactic awareness. The predictive value of each of these measures will be briefly examined in this section