The Evidence
None Of This Is A Guess.
MS is a condition of variability. The evidence below is why the word ladder steps down and back up without moving a single surviving word, and why the display runs bold and calm.
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Every finding below names its sources. Where the field has no evidence, we say so instead of implying otherwise. Where Grand Voice OS goes beyond the literature, we mark it as our extension, not as a study result. Ask us for any source in full: admin@titaniumdigitalholdings.com.
What The Evidence Says
Progressive disclosure, hiding words on hard days and restoring them on good ones, is strong practice consensus with zero empirical AAC studies behind it. We say that plainly. What IS replicated is that surviving words must never move, and the 48/24/12 ladder obeys exactly that.
Practice consensus; location evidence per Thistle 2018
Consistent symbol location is the single best-replicated learnability finding in AAC research. Motor plans build around position, and moving a word costs the user the practice they paid for. Every GVOS board obeys this as law.
Thistle 2018; Dukhovny & Gahl 2014
Typical aided communication runs 8 to 10 words per minute. Phrase-based prestored speech measured 36 to 64 words per minute. That is why banked phrases, pinned folders, and one-tap libraries sit at the center of the system.
Todman 2000
Target size, spacing, dwell behavior, and layout stability for gaze input have a real literature. The eye-gaze surfaces are built against it, and calibration keeps learning the user's eyes.
Feit 2017; Niu 2021; Drewes 2014; Dukhovny & Zhou 2016; COGAIN guidelines; Fager 2019
Roughly one in three AAC devices ends up abandoned, and the drivers are support factors: training, caregiver enablement, upkeep, and vocabulary relevance. The kit ships with the family guide, coached phrase authoring, and a companion that teaches, because the device that stays in use is the one the whole household knows how to live with.
Phillips & Zhao 1993; Johnson 2006; Moorcroft 2019, 2020; Pape 2002
Still Being Compiled
The dossier grows. These are the source sets currently being compiled for this page, named so the gap is visible instead of hidden: