Human-Computer Interaction for CSAI

by Albert Major

1. WARM-UP: UNDERSTANDING USABILITY & AFFORDANCES

Google vs. Craigslist Comparison

Google's Interface:

• Primary function: Searching
• Key design element: Prominent search text box immediately visible when you open the page
• Affordance: The text box "offers" you the ability to type and search
• Definition reminder: Affordance = what an interface element offers or allows you to do

Craigslist's Interface:

• Design characteristics:
  • All text appears in same color, font, and size
  • Minimalist/brutalist design approach
  • Lots of text categories listed without visual hierarchy
• Student critique: Hard to find what you're looking for without reading everything; poor visual differentiation
• Counter-argument: Functionality and usability are actually good for their target users

Key Lesson: Don't Judge Without User Research

• Critical insight: You cannot determine if a design is "good" or "bad" without asking the actual users
• Reality: Craigslist users are actually happy with the interface despite it appearing cluttered
• Why it works for them:
  • Users typically come with a specific goal (posting an ad or searching in a known category)
  • They navigate directly to one category
  • They're not doing complex searches across the site
  • The simple posting process works well for their needs
• Design lesson: What looks "bad" to an outsider might be perfectly functional for the target audience
• Important principle: Always conduct user research before making design judgments