The statistical learning view of word reading and spelling is based on the ideas that writing systems have a rich statistical structure and that people implicitly pick up this structure as they learn to read and write. Whereas laboratory studies stress the speed and power of statistical learning, the evidence we review shows that adults with years of reading and writing experience do not always mirror the statistics of their writing system in their behavior. We consider possible reasons for these discrepancies, including the complexity of the statistical relationships, ease of production, and satisficing. The findings suggest that literacy instruction should address the probabilistic patterns in writing systems and the role of context in selecting appropriate pronunciations and spellings.