1.1. Style guides
The design follows branding or style guides that dictate the use of logos, color, and typography.
Eva Kaniasty's CARMEL Guidelines distill usability into a memorable acronym — Consistent, Accessible, Responsive, Memorable, Efficient, Likeable — each with its own set of supporting criteria. The guideline was designed to be easy to teach and fast to apply, so product teams and stakeholders without a formal UX background can contribute to evaluations.
That makes CARMEL particularly useful for organizations building a usability practice from scratch: new hires can reach for the acronym on day one, designers can use it to structure a design review, and engineers can reference it in a PR comment without needing to cite an academic paper.
The criteria themselves are pragmatic rather than exhaustive. You won't catch every accessibility edge case with CARMEL alone — for that, pair it with WCAG or ISO 9241 — but you will quickly cover the human-factor basics that cause the majority of user frustration. Use CARMEL as a shared vocabulary across design, product, and engineering, and layer in deeper guidelines when the product needs them.
1.2. Design patterns
The design follows a cohesive set of human interface guidelines or design patterns.
1.3. Naming conventions
Naming conventions are consistent across pages and widgets.
1.4. Look & feel
Layouts and page elements have a cohesive look and feel.
1.5. Interactions
Similar interactions and design patterns behave consistently.
2.1. Font size
The design meets minimum font size legibility guidelines.
2.2. Contrast
The design meets guidelines for minimum contrast between foreground, text and background.
2.3. Double coding
Visual information is 'double-coded' for accessibility by users with color blindness or other visual impairments.
2.4. Target size
The design meets guidelines for minimum target size for mouse and touch targets.
2.5. Screen Readers
The design meets W3C's Web Content Accessibility Guidelines (WCAG) for users of screen readers.
3.1. Confirmation dialogs
The design meets minimum font size legibility guidelines.
3.2. Undo functions
Undo functions prevent major data loss and unintended consequences.
3.3. Error messages
Error messages include instructions for recovery.
3.4. Version control
Version control, history or archiving functions are built into data intensive or collaborative workflows.
3.5. System recovery
The system mitigates impact of catastrophic errors, crashes, and network outages.
4.1. Limited choices
Lists of critical choices (menu options, navigation categories) are visible in a single view, or limited to <10 items.
4.2. Automatic calculations
The system 'does the math' for the user.
4.3. Feedback
Microcopy and microinteractions provide ongoing feedback to the user.
4.4. Chunking and masking
Long strings of text or numbers (security codes, phone numbers) are visually chunked or masked.
4.5. Security practices
Security systems reduce need for spontaneous recall by utilizing password best practices, 2-step-authentication, or single sign-on.
5.1. Shallow navigation
Navigation hierarchy is no more than 3 or 4 levels deep.
5.2. Responsive layouts
Layouts are responsive, or optimized for the screen size of target devices.
5.3. Navigation shortcuts
Navigation breadcrumbs, progress trackers, and keyboard shortcuts improve findability.
5.4. Accelerators
Autocomplete, auto-detect and other accelerators improve task speed.
5.5. Autosave
Auto-save and/or cookies maintain session state and prevent accidental data loss.
6.1. Internal language
Branded vocabulary, internal language, and marketing jargon is used sparingly, and absent from navigation, menus, and buttons.
6.2. Technical jargon
Technical or system jargon is absent from error messages and other microcopy.
6.3. Acronyms
Acronyms include access to definitions, and appear in narrative content only.
6.4. Plain language
Technical, legal, and other potentially difficult-to-understand content is written in plain language.
6.5. Readability level
Content readability level is appropriate for the target audience(s).
See it in action
Kaniasty's CARMEL guidelines, on a live URL, in one click.
Click anywhere on a real page, drop a heurio, pick the Kaniasty's CARMEL guidelines rule it violates. No screenshots, no Loom, no separate doc.