Spelling is an under-researched and often under- taught elementary school subject. This book details an investigation of traditional versus extended word study spelling instruction that includes results of 3rd graders' spelling achievement. Traditional spelling instruction was based on the use of spelling lists from 3rd grade basal readers. The extended word study instruction brought together the Words Their Way "word study" curriculum plus the use of reliable spelling generalizations. Overall spelling achievement, general spelling knowledge, transfer of spelling knowledge and ability to verbalize spelling knowledge were measured. Extend word study significantly improved overall spelling development, ability to discuss common spelling usage patterns and transfer of spelling knowledge to unfamiliar low-frequency words. This book will be helpful to elementary school administrators and teachers interested in how to provide engaging and evidenced-based spelling instruction that is integrated into a literacy framework.