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AAC Standards · Reviewed 25 September 2026

AAC quality, evidence and open standards

SymbolTiles is designed to support communication and communication-partner practice. It is not a complete replacement for an individually assessed AAC system, and no single system meets every person's needs across every setting. Selection and ongoing review should be person-centred and, where appropriate, involve an AAC-experienced speech pathologist and the person's wider team.

Implemented in SymbolTiles

  • Words, symbols and photographs in configurable grids, with visible text labels.
  • An always-available, editable core-word row alongside activity-specific vocabulary.
  • Stable tile positions during a talker session, plus a 72 px SymbolTiles minimum for fitted tiles.
  • Sentence construction, speak, clear, backspace, grammar forms, saved messages and communication-repair phrases.
  • Independent visible labels and spoken messages for concise tiles that can voice fuller phrases.
  • Optional speak-on-tap and clear-after-speaking behaviour.
  • Partner modelling guidance that does not require the AAC user to copy a model.
  • Learner profiles for voice, rate, core vocabulary, direct selection, touch-and-hold dwell, one-switch scanning, auditory scanning, partner-assisted scanning, activation timing, repeat filtering, spacing and high contrast.
  • Opt-in, on-device aggregate word counts only; no sentence histories, word pairs or timestamps.
  • Open Board Format single-board (.obf) and packaged multi-board (.obz) import/export, including linked-board Talker navigation and packaged images where available.
  • Printable PDF/PNG materials as a light-tech backup and plain-text copying for use in other apps.

Known limits and roadmap

These are important AAC capabilities, but SymbolTiles does not claim to support them yet.

  • Native eye-tracker integration and device-specific head-mouse or joystick controls beyond standard pointer/keyboard compatibility.
  • A full keyboard board, word prediction, bilingual same-board vocabulary and language-specific inflection sets.
  • Recorded voice/message banking, offline generated voices and full offline board use.
  • Formal usability testing with a diverse panel of people who use AAC and communication partners.

Sources and acknowledgement

Product decisions were informed by OpenAAC's community-developed considerations and Open Board Format, alongside professional AAC guidance and WCAG. This acknowledgement does not imply that OpenAAC, Speech Pathology Australia, ASHA or W3C certifies or endorses SymbolTiles.

Open Board files retain board and image licence fields when present. If an imported resource has no licence, the Open Board specification says it should be treated as private/all rights reserved; importing a file does not grant permission to redistribute its images.

Evidence log

Last updated 25 September 2026

The research, professional guidance and standards behind SymbolTiles design decisions, with how strong each source is and who it was studied with. Strength describes the source itself, not how well SymbolTiles applies it.

  • Accessibility of controls

    Strength: Guidance onlyApplied

    Decision: Talker controls are designed against WCAG 2.2, including visible keyboard focus and generous target sizes (SymbolTiles uses a 72 px minimum for fitted tiles, well above the WCAG minimum).

    What the source says
    Web accessibility success criteria for keyboard focus visibility and minimum pointer target size.
    Population and limits
    General web accessibility standard, not AAC-specific. SymbolTiles has not had a formal WCAG conformance audit.
    Evidence type
    Technical standard
    Logged
    22 August 2026
    Applies to
    Talker, Talker controls, Scanning and keyboard access
    Citation
    W3C (2023). Web Content Accessibility Guidelines (WCAG) 2.2 — Focus Visible (2.4.7) and Target Size (Minimum) (2.5.8).
    Source
  • Interoperability

    Strength: Guidance onlyApplied

    Decision: Boards import and export as Open Board Format single boards (.obf) and packaged multi-board sets (.obz), including linked boards, images and licence fields where present.

    What the source says
    A community-developed open file format so people can move their vocabulary between AAC apps. Resources without a licence should be treated as all rights reserved.
    Population and limits
    An interoperability format, not evidence about communication outcomes. Not every app supports every field.
    Evidence type
    Technical standard
    Logged
    22 August 2026
    Applies to
    Open Board import/export, Talker navigation
  • Motor planning and stable positions

    Strength: Guidance onlyApplied

    Decision: When a board is locked, every tile keeps its page, row and column across screen sizes, export and reload. A different device may scale or letterbox the board, but must not silently reflow columns.

    What the source says
    The audit found the lock preserved tile order but not geometry: the responsive grid could change column count by screen size, and Open Board export compacted empty positions. Both were patched on 25–26 September 2026 (locked boards keep their saved grid; export writes buttons by slot and keeps empty spaces).
    Population and limits
    Professional consensus and internal engineering review; no specific study is cited here. The patch passes automated checks but has not yet been verified on a physical device or a saved learner board. Individual needs vary and layout changes should be reviewed with the person's team.
    Evidence type
    Internal audit
    Logged
    25 September 2026
    Applies to
    Talker, Locked boards, Open Board export
    Citation
    SymbolTiles internal audit: docs/AAC_ARCHITECTURE_AUDIT_2026-09-25.md (Motor Stable architecture and invariants), reflecting widely shared AAC practice guidance on consistent motor locations.
  • Privacy of communication

    Strength: Guidance onlyApplied

    Decision: Usage tracking is opt-in, on-device aggregate word counts only. SymbolTiles does not store message histories, word pairs or timestamps.

    What the source says
    What a person says with AAC is their private communication; data collection is kept to the minimum useful for vocabulary review.
    Population and limits
    An internal design principle, not research evidence.
    Evidence type
    Internal decision
    Logged
    22 August 2026
    Applies to
    Talker, Learner profiles, Word counts
    Citation
    SymbolTiles internal privacy decision.
  • Role of SymbolTiles in AAC

    Strength: Guidance onlyApplied

    Decision: SymbolTiles supports, but does not replace, an individually assessed AAC system. Partner modelling guidance shows words without requiring the AAC user to copy the model.

    What the source says
    AAC selection and review should be person-centred and involve an AAC-experienced speech pathologist and the person's wider team.
    Population and limits
    Professional guidance summarising practice; not a study of SymbolTiles.
    Evidence type
    Professional body guidance
    Logged
    22 August 2026
    Applies to
    Talker, Partner modelling, Help & Guide
    Citation
    Speech Pathology Australia: Augmentative and Alternative Communication.
    Source ASHA Practice Portal: Augmentative and Alternative Communication
  • Symbol tile colour

    Strength: LimitedApplied

    Decision: Talker tiles keep a white background. Word-type colour is an optional thin edge, off by default, rather than a full coloured tile background.

    What the source says
    Most children responded faster when symbols had white backgrounds, but the difference was not statistically significant. The internal colour of a symbol influenced visual search; background colour cues did not clearly help. The authors urge caution about using background colour.
    Population and limits
    Young children without disabilities, in an experimental task. Results may not transfer directly to people who use AAC, to other ages, or to everyday communication.
    Evidence type
    Peer-reviewed study
    Logged
    25 September 2026
    Applies to
    Talker, Talker redesign, Board tiles
    Citation
    Thistle, J. J., & Wilkinson, K. M. (2017). Effects of background color and symbol arrangement cues on construction of multi-symbol messages by young children without disabilities: Implications for aided AAC design. Augmentative and Alternative Communication, 33(3).
    Source