"Words Their Way"[TM] is an approach to phonics, vocabulary, and spelling instruction for students in kindergarten through high school. The program can be implemented as a core or supplemental curriculum and aims to provide a practical way to study words with students. The purpose of word study (which involves examining, manipulating, comparing, and categorizing words) is to reveal logic and consistencies within written language and to help students achieve mastery in recognizing, spelling, and defining specific words. The What Works Clearinghouse (WWC) identified 29 studies of "Words Their Way"[TM] for beginning readers that were published or released between 1983 and 2012. One study is within the scope of the Beginning Reading review protocol but does not meet WWC evidence standards. The study uses a quasi-experimental design but does not establish that the comparison group was comparable to the intervention group prior to the start of the intervention. Fifteen studies are out of the scope of the Beginning Reading review protocol because they have an ineligible study design. Eleven studies are literature reviews or meta-analyses. Four studies do not use a comparison group design, a regression discontinuity design, or a single-case design. Thirteen studies are out of the scope of the Beginning Reading review protocol for reasons other than study design. Eleven studies do not use a sample aligned with the protocol--the sample does not fall within the Beginning Reading grade range of K-3. Two studies include fewer than 50% general education students. A glossary of terms is included. (Contains 3 endnotes.)