A theory of how children progress through different phases of reading should be an asset both to reading researchers and teachers alike. The present paper provides a brief review of Ehri's influential four phases of reading development: pre-alphabetic, partial alphabetic, full alphabetic and consolidated alphabetic. The model is flexible enough to acknowledge that children do not necessarily progress through these phases in strict sequence. Such flexibility is perhaps both a strength and a weakness. Despite some minor problems (such as weak operational definition, little attempt to relate to underlying developing cognitive structure, a final phase that seems removed from mature skilled reading) the model has served reasonably well as a flexible framework rather than as a set of falsifiable scientific hypotheses.