Edge cases
Category: Design
What are Edge Cases?
Edge Cases are unusual, rare or exceptional situations that can occur when using a product or service. These are scenarios that deviate from the "normal" or "ideal" user path.
In the context of UI/UX design, edge cases represent situations that are not the main focus of the design, but must be taken into account to create a complete and sustainable user experience.
Types of Edge Cases in UI/UX:
1. Edge Cases related to data
Examples:
- Empty states - when there is no data to display
- Long texts - names, titles, descriptions
- Short texts - one-letter names
- Special symbols - emojis, HTML code
- Large numbers - sums, quantities, dates
- Zero or negative values
2. Edge Cases related to user behavior
Examples:
- Quick sequence of actions - multiple button clicks
- Action cancellation - the user gives up halfway through
- Change of decision - returning and editing
- Simultaneous actions - from multiple tabs or devices
- Unexpected navigation - back/forward in the browser
3. Edge Cases related to technical aspects
Examples:
- Poor internet connection - delay or interruption
- Different screen sizes - from small mobile to large monitors
- Different browsers and devices
- Missing permissions - camera, location, notifications
- Server problems - errors 404, 500, timeout
4. Edge Cases related to business rules
Examples:
- Account limitations - trial versions, paid accounts
- Time limitations - expiring offers, sessions
- Geographical limitations - regions, languages, currencies
- Legal requirements - GDPR, cookie consent
- Specific user groups - administrators, moderators
Why are Edge Cases important?
Improved user experience
Users feel understood and secure, even in unusual situations
Reduced support
Reduces the number of errors and requests to support
Increased trust
Users develop trust in the product when it handles unexpected situations well
Competitive advantage
Attention to details distinguishes good products from excellent ones
Preventing critical errors
Many edge cases can lead to serious problems if not handled
Methods for identifying Edge Cases:
User Story Mapping
Reviewing alternative and exception scenarios for each user story
"What If" sessions
Brain storming with the team: "What if..."
Usability tests
Observing real users and their unexpected behaviors
Error analysis
Reviewing logs, errors and requests to support
Personas and scenarios
Creating diverse personas with different needs and behaviors
Strategies for handling Edge Cases:
1. Prevent (Preventing)
Change the design to avoid edge case
Example: Limiting the length of text fields to avoid long texts
2. Detect (Detecting)
Identify the edge case and provide an appropriate message
Example: Showing "No results found" when there are no search results
3. Recover (Recovering)
Provide a way for the user to return to normal state
Example: Button "Back" or "Cancel" when there is an error in the payment process
4. Graceful Degradation
The product continues to work, even with limited functionality
Example: Showing a basic version of the site when JavaScript is missing
Good practices for managing Edge Cases:
- Start with happy path - design the main scenarios first
- Document edge cases - create a list and prioritize
- Collaborate with developers - they often identify technical edge cases
- Test regularly - include edge cases in test scenarios
- Be proactive - don't wait for users to report problems
- Iterative approach - continuously improve handling of edge cases
- Plan time - set aside time specifically for edge cases in the project plan
Common mistakes:
- Ignoring edge cases - "this won't happen"
- Too much attention - optimizing for 1% of users at the expense of 99%
- Complex solutions - overly complex designs for rare situations
- Lack of prioritization - treating all edge cases equally
- Forgetting internationalization - different lengths of text on different languages