Parents looking for direct instruction materials and programs should look into the Hooked on Phonics series and other related products. Critics argue that direct instruction is nothing but canned teaching with little room for the personalization of lesson plans.  To these critics, schools that require direct instruction are handcuffing their best teachers and providing a crutch to their worst ones.  This argument fails to address the fact that good teachers will be successful with any lesson plans, including direct instruction. The effectiveness of direct instruction is supported by substantial research, but there are some recent longitudinal studies which raise doubts about its effectiveness.