Orton GIllingham is defined by these seven principles:
Direct and Explicit
The instructor presents the material in direct and explicit fashion. Never is the student expected to know anything that has not been taught and practiced.
Diagnostic and Prescriptive
Always, the teacher seeks to understand how an individual learns and to devise appropriate teaching strategies. Each lesson is planned to a particular student. Infinitely adaptable, Orton-Gillingham is flexible; it is an approach rather than a system.
Language Based
The Orton-Gillingham approach is based on a technique of studying and teaching language, understanding the nature of human language, the mechanisms involved in learning, and the language learning process in individuals.
Multisensory
The Orton-Gillingham approach is multisensory. Sessions are action-oriented with auditory, visual, and kinesthetic elements reinforcing each other for optimal learning. Spelling is taught simultaneously with reading. In this respect Orton-Gillingham differs from traditional phonics instruction.
Structured, Sequential and Cumulative, but Flexible
The elements of the language are introduced systematically. Students begin by reading and writing sounds in isolation. These are blended into syllables and words.
The various elements of the language - consonants, digraphs, blends, and diphthongs- are introduced in orderly fashion. As students learn new material, they continue to review old material to the level of automaticity. The teacher addresses vocabulary, sentence structure, composition, and reading comprehension in a similar structured, sequential, and cumulative manner.
Cognitive
Students learn about the history of the language and study the many generalizations and rules that govern its structure. Again and again, they are encouraged to think rather than to guess.
Emotionally Sound
Because old material is constantly reviewed and new material is introduced systematically, the student experiences a high degree of success in every lesson and gains in confidence as well as in skill. Thus, self-esteem develops directly from the student's achievement and learning becomes a positive experience.
(Garside Institute for Teacher Training, 2019)