"Evidence-based" means that an approach has proven effective in rigorous clinical trials, as published in peer-reviewed professional journals.
Scientific studies by the National Reading Panel identified several common content areas in effective reading programs: phonemic awareness (ability to recognize and manipulate sounds in words), phonics (ability to associate sounds with written symbols), fluency (quick, accurate and expressive reading/writing), vocabulary, and comprehension. In addition, effective methods of instruction are explicit, systematic, cumulative, multimodal and responsive. Finally, successful outcomes for dyslexic learners are highly dependent on early intervention, intense instruction, highly qualified instructors and sufficiently long duration.
Here are common terms that refer to effective intervention approaches:
Structured Literacy: an umbrella term used by the International Dyslexia Association (IDA) to describe programs that adhere to the content and methods outlined above
Orton-Gillingham approach (OG): an approach that follows the sequential, multi-sensory techniques developed by Dr. Orton, Anna Gillingham and colleagues. OG instructors complete rigorous training to become certified. Most methods or programs for dyslexia are derived from OG principles.
Multisensory/multimodal instruction: instruction that incorporates visual, auditory and kinesthetic-tactile input to strengthen neural pathways connecting speech to print
Slingerland: a classroom adaptation of the OG approach, which certifies teachers after rigorous training and demonstration of mastery
PDF article by literacy expert Louisa Moats explaining principles and components of structured literacy
Link to OG website page explaining the approach and its origins
Classroom-adapted literacy approach based on Orton-Gillingham principles of multi-sensory learning (used at North Bridge Academy). Site includes basic information about this approach, as well as a list of Slingerland-certified tutors.