Today almost nobody, either inside or outside the teaching profession, has even heard about the world's largest, longest, and most expensive educational experiment. As large as it is, Project Follow-Through is just a tiny fraction of the 20th century's enormous body of research supporting the use of comprehensive, systematic phonics in teaching young children to read. The central problem of early reading is word recognition - teaching children how to determine which words are on the page. Phonics critics believe that children who use context clues will develop better critical thinking skills than children who recognize words using phonics. Students will presumably then improve their future performance by making inferences about the deductions that they have used in the past.
Children using context clues learn to accept inaccuracy and failure.
The use of context clues teaches little, if anything, specific about critical thinking. The problem is that there is no systematic framework, because each deduction is done within a new context. The huge universe of potential combinations of contexts and words also precludes the possibility of learning or using inference skills, since little can be inferred from large numbers of generally unrelated situations. Even though a phonics teacher is not explicitly trying to teach logic to his or her students, it is simply impossible to avoid doing so. The logic lessons of phonics are taught by example during the learning and the application of phonetic rules.