Map how a product or feature works across the full spectrum of human ability — not just 'can use' and 'can't use'. Use when planning accessibility coverage, identifying gaps, or communicating accessibility scope to stakeholders. Triggers on: ability spectrum, range of users, who can use this, who can't use this, accessibility coverage, accessibility scope, ability range, spectrum of needs.
Map how a feature performs across the full range of human ability — from full capability to no capability in each dimension — to identify where the design starts to break down and who gets excluded.
Accessibility is not binary. It's not "can see" vs "blind." The reality is a continuous spectrum:
Products don't go from "works" to "doesn't work" in a single step. They degrade gradually. The spectrum map shows you exactly where your design starts failing and for whom.
Identify the 5–10 most important tasks a user performs with the product.
For each relevant ability dimension, define 4–5 points:
Vision spectrum: Full vision → Corrected vision → Low vision (magnification) → Very low vision (screen reader + some vision) → No vision (screen reader only)
Hearing spectrum: Full hearing → Mild loss (louder volume) → Moderate loss (captions needed) → Severe loss (captions + visual alerts) → Deaf (fully visual communication)
Motor spectrum: Full dexterity → Reduced precision (larger targets) → Limited range (keyboard only) → Minimal movement (switch or voice) → No hand use (eye tracking, sip-and-puff)
Cognitive spectrum: Comfortable with complexity → Prefers simplicity → Needs plain language → Needs step-by-step guidance → Needs significant support
For each task × ability point, rate:
Where does the design shift from "works" to "fails"? That breakpoint is your accessibility boundary. Everything to the right of it is excluded.
The goal is to push that boundary as far right as possible.
The spectrum map is a powerful communication tool because it shows:
| Task | Full vision | Low vision | Screen reader |
|---|---|---|---|
| Search for a product | Works well | Works with friction (small targets) | Fails (search suggestions not announced) |
| Complete checkout | Works well | Works well | Works with friction (form errors not associated) |