01-04 · Week 1
Design rules: standards, guidelines, principles and patterns
The four kinds of design rule ordered by generality and authority, Shneiderman and Nielsen compared, the notable design principles, and patterns, anti-patterns and dark patterns.
- Order standards, guidelines, principles and patterns by generality and authority.
- Recall Shneiderman eight golden rules and Nielsen ten heuristics and spot where they overlap.
- List the notable design principles and the three groups the lecture sorts them into.
- Define design pattern, anti-pattern and dark pattern.
18 min readJump to the quiz ↓
Rules differ in how widely they apply and how strictly they bind
Intuition
“Make it consistent” and “buttons must meet ISO requirement X” are both design rules, but you can break the first when you have a good reason and you cannot ignore the second. Lecture 1 sorts rules by two properties: generality and authority.
The lecture’s slide arrows run in opposite directions. Generality increases towards abstract principles. Authority increases towards standards. That gives the ordering to remember.
| Rule | What it is | Generality | Authority |
|---|---|---|---|
| Standards | Govern large communities. Processes, specifications or definitions built on concrete theories | Low | High |
| Guidelines | Best practices and recommendations, often technology-oriented | Middle | Middle |
| Principles | Abstract, from theory, experience and common sense | High | Low |
| Patterns | Generative collection of common practice, not necessarily good practice | Varies | Low |
The slide arrows place standards and principles at the two ends. The middle positions of guidelines and patterns are inferred from the lecture descriptions, because the diagram labels were partly lost in extraction. Worksheet 1 asks you to fill this table in with High or Low and an example.
Standards and guidelines give concrete, checkable advice
The standard the lecture names is ISO 9241-11:2018 Ergonomics of HCI, Part 11. It provides a framework for understanding the concept of usability and applying it where people use interactive systems, other systems, products and services. The lecture’s reading task asks which standard is most relevant for you to know.
Guidelines promote consistency among similar products within the same company. Two families appear: guidelines for mobile app development (iOS Human Interface Guidelines, Google Material Design), and guidelines for interface design in general (Shneiderman’s eight golden rules, Nielsen’s ten usability heuristics).
Compare
Shneiderman eight golden rules
- Strive for consistency
- Enable frequent users to use shortcuts
- Offer informative feedback
- Design dialogs to yield closure
- Offer error prevention and simple error handling
- Permit easy reversal of actions
- Support internal locus of control
- Reduce short-term memory load
Nielsen ten usability heuristics
- Visibility of system status
- Match between system and real world
- User control and freedom
- Consistency and standards
- Error prevention
- Recognition rather than recall
- Flexibility and efficiency of use
- Aesthetic and minimalist design
- Help users recognise, diagnose and recover from errors
- Help and documentation
Exam detail
Lists are the likely test: eight for Shneiderman, ten for Nielsen. Overlaps worth knowing: consistency (both), feedback and visibility of status, short-term memory load and recognition rather than recall, shortcuts and flexibility and efficiency, error prevention (both). The slide did not draw the matching lines, so the pairings here are read from the wording.
Pitfall
Do not move rules between the lists. “Aesthetic and minimalist design” is Nielsen. “Design dialogs to yield closure” and “support internal locus of control” are Shneiderman.
Principles and patterns are broader and softer
Design principles are derived from a mix of theory, experience and common sense and can apply to many design situations. The lecture names six notable ones: visibility, consistency, affordances, feedback, constraints and mapping. It also groups them by what they serve: learnability (visibility, consistency, affordances, familiarity), sense of control (feedback, control, mapping, navigation) and safety (constraints, recovery). The two-column slide layout was garbled in extraction, so treat the exact group membership as approximate and check the PDF.
A design pattern describes a problem, a solution and where the solution has been found to work. Patterns evolve as people use them, experience increases and preferences change, and they depreciate when outdated. An anti-pattern is a design approach that represents poor practice. A dark pattern is a design that tricks people, championing stakeholder value over user value.
Pitfall
Patterns are “common practice”, not “best practice”. A widely copied design can still be a bad one, which is why anti-patterns and dark patterns exist as separate ideas.
Recall
Which kind of design rule has the highest authority and which has the highest generality?
Standards have the highest authority and the lowest generality. Principles have the highest generality and the lowest authority.