One reference point: The recommendations for Wilson, which is an OG intervention:

http://www.wilsonlanguage.com/programs/wilson-reading-system/

Note that small group intervention is recommended as 5x45-90, while individual tutoring ranges from 2-5x60-90 minutes.

Page 5 of this document summarizes recommended frequency of intervention sessions for a number of variants:

https://www.winsorlearning.com/imag...ix-of-Multisensory-Language-Programs.pdf

I saw the 2x30 in a poster presentation about two years ago, so that research may not have been published yet, as it was probably part of someone's dissertation work.

Last edited by aeh; 01/25/16 11:28 AM.
...pronounced like the long vowel and first letter of the alphabet...