Spelling Mastery is a six-level Direct Instruction series that teaches students dependable spelling skills by blending three approaches: phonemic, whole-word, and morphemic. Each approach has advantages and possible disadvantages. Spelling Mastery is designed to maximize the advantages of each approach while minimizing its disadvantages.

The whole word approach focuses on memorization. Spelling Mastery does not use memorization for words that contain predictable phonemic elements, but reserves memorization for words that have irregular letter-sound relationships (i.e feud, break, gone). Prompts are used to make the initial learning easier, and systematic practice is provided to facilitate retention.

The phonemic approach is used for letter-sound correspondences that are predictable. For example, the sound /ar/ is highly consistent. In about 95 percent of the words in which the sound /ar/ is said, the sound is spelled with the letters a-r. The authors conducted a careful analysis of phoneme-grapheme relationships, and the generalizable relationships were systematically introduced and practiced.

The morphemic approach combines roots, bases, prefixes, and suffixes into words. The morphemic approach used is highly similar to that used in Spelling Through Morphographs. Students combine morphographs to write words and do exercises in which they indicate the morphographs in words. The use of morphographs to determine the meanings of words gradually increases as students progress through the levels.