🎨 Good Design vs Bad Design

User Experience (UX) & Human-Computer Interaction (HCI)

Why are some apps a joy to use and others make you want to throw your phone? It's all about design. Learn what makes interfaces good or bad.

DigiTech A-Level §2.1.4 CS GCSE §1.7

🤔 What is UX?

UX (User Experience) = how it feels to use something. Is it frustrating or delightful?

HCI (Human-Computer Interaction) = the study of how people interact with computers and how to design better interfaces.

UI (User Interface) = what you actually see and click — buttons, menus, colours, layout.

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Spot the Design Problems

Look at these interfaces and spot the usability problems. Click "Reveal" to see the issues.

📖

The 8 Rules of Good Interface Design

Based on Nielsen's Usability Heuristics (simplified for your exam):

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Visibility
Users should be able to see what they can do. Important buttons should be obvious, not hidden in menus.
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Feedback
The system should respond to every action. Click a button → something should happen (loading spinner, colour change, message).
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Consistency
Same action = same result everywhere. If blue text means "clickable" on one page, it should mean the same on every page.
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Error Prevention
Design so users can't make mistakes easily. "Are you sure you want to delete?" prevents accidental data loss.
↩️
Undo / Recovery
Users should be able to undo mistakes. Ctrl+Z, "Go back", recycle bin — always provide an escape route.
♿
Accessibility
Works for everyone — colour blind users, screen readers, keyboard-only users. Good contrast, alt text on images, scalable text.
🧹
Simplicity
Don't overload the user. Show only what's needed. Every extra button, menu or option adds confusion.
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Affordance
Things should look like what they do. A button should look clickable. A slider should look draggable. A link should look different from normal text.
♿

Colour Contrast Checker

Good design means text is readable for everyone. Check if your colour combination passes accessibility standards (WCAG).

Sample Text — Can you read this easily?
📝 Exam tip: UX questions often give you a screenshot and ask you to evaluate the interface. Use the 8 principles above as a checklist. Also know the difference between UI (what it looks like), UX (how it feels), and HCI (the academic study of human-computer interaction).