top of page

The Story of SIS

Sandra Dillon, Author

In 1972, Sandra Dillon embarked on a mission to discover ways to provide more effective education for students with specific language disabilities. Inspired by the works of Dr. Samuel T. Orton and Anna Gillingham, Sandra's pursuit of answers led her to influential educators.

Sounds In Syllables Student Book 1
Sounds In Syllables Student Book 2

SIS Methodology 

In developing SIS, Sandra Dillon integrated teaching methods learned directly from Patricia and Charles Lindamood, Beth Slingerland, and Aylett Royal Cox, the author of Alphabetic Phonics. Over 21 years, her collaboration with students and colleagues at the Albuquerque Public Schools' Language Clinic for dyslexic students played a pivotal role in shaping the SIS program.

SIS Legacy

Sounds In Syllables represents the culmination of Sandra Dillon's journey, influenced by the groundbreaking work of Orton, Gillingham, and other educators. Sandra's dedication to addressing the unique needs of dyslexic learners led to the creation of an approach designed to provide effective, personalized instruction.

Sounds In Syllables Student Book 3
Sounds In Syllables Sudent Book 4

Acquisition by ASDEC

In 2023, the Atlantic Seaboard Dyslexia Education Center (ASDEC) acquired SIS Publishing  from Sandra Dillon. This acquisition ensures that current and future Academic Language Therapists will have secure access to the power of SIS for their students.


About ASDEC 

ASDEC is a 501(c)(3) non-profit training and advocacy center headquartered in Rockville, MD, dedicated to preventing academic failure through evidence-based multisensory reading and math instruction. Our founder, Claire Nissenbaum, F/AOGP. M.A., CAT established ASDEC in 2000 to help dyslexic children and adults overcome barriers to learning. Along with the clinical psychologist Betty Levinson, with whom she had partnered since 1974, Ms. Nissenbaum developed the only training center in the Washington, DC region that offers IMSLEC accreditedIDA endorsed evidence-based structured, multisensory techniques in language skills (decoding, fluency, spelling, writing, vocabulary, and comprehension) and  math. Built on close to 50 years of Orton-Gillingham based training, ASDEC  is recognized by educational psychologists, parents, school administrators and advocates as being the highest quality in the field of dyslexia and learning disabilities.

Sounds In Syllables Student Book 5
bottom of page