Affordance Concepts in HCI

Affordance Concepts

• Affordances describe the relationship between objects and their potential for action
• Affordances bridge perception and interaction, widely discussed in Human-Computer Interaction (HCI) and psychology
• Bill Gaver introduced affordances to interface design
• Gaver's focus is understanding affordances as perceptible or hidden
• Perceptible affordances are clear and direct cues, while hidden affordances are functionalities not immediately visible
• Example of a perceptible affordance: a transparent door with a handle that affords pulling
• Rex Harton extended the concept to emphasize the interaction between individuals and environments
• Harton's Insight: Affordances vary based on individual abilities and situational factors
• Example: A pathway affords walking only if it is accessible and navigable
• Types of Affordances: Physical, Sensory and Functional

Physical Affordances

• A button affords pressing
• A handle affords gripping

Sensory Affordances

• Sensory affordances relate to perceptual cues provided by an object
• Key characteristics: engage users through sight, sound, touch, or other senses, facilitate interaction by guiding perception
• Examples include a bright icon on a screen affording attention, and a textured surface affording touch

Functional Affordances

• Functional affordances relate to the purpose or function of an object
• Key characteristics: focus on how objects enable specific tasks or actions, often tied to the usability of tools and systems
• Examples: a calculator affords mathematical operations, and a search bar affords finding information

Conclusion

• Summarizing affordances and hidden affordances in design
• Gaver's focus: Perceptible and hidden affordances in design
• Harton's insight: Affordances are shaped by context and individual abilities
• Types of affordances: Physical, sensory, and functional affordances guide action and interaction
• Recognizing affordances leads to effective and intuitive design.