At a Glance Notes: [Chapter 3] Users Physical Capabilities
1. Human Capabilities and Limitations
Definition: The fundamental principle that drives all good interface design - understanding the specific capabilities and limitations of humans to create experiences that work with human nature rather than fighting against it. Subtopics/Characteristics:
- Visual channel
- Auditory channel
- Haptic channel
- Movement
- Information processing limitations
- Four main physical interaction channels
2. Visual Channel
Definition: How humans see and process visual information, including the eye’s mechanism and the various limitations and quirks of the human visual system that directly impact interface design. Subtopics/Characteristics:
- Retina (Cones vs. Rods)
- Peripheral vision
- Motion detection
- Color blindness
- Context effects
- Visual illusions
- Size constancy
- Depth perception
- Word shape recognition
- ALL CAPS readability issues
- Visual pattern processing
3. Auditory Channel
Definition: How humans hear and process sound information, including the ability to filter and focus audio input, used strategically in interface design for feedback, attention, and location cues. Subtopics/Characteristics:
- Hearing frequency range (20Hz to 15kHz)
- Cocktail party phenomenon
- Attention filtering
- Feedback provision
- Location cues
- Alert systems
- Background noise processing
- Age-related hearing changes
4. Haptic Channel
Definition: The sense of touch and physical feedback that provides crucial environmental information and can serve as the primary sense for accessibility, especially for visually impaired users. Subtopics/Characteristics:
- Tactile sensitivity variations
- Keyboard feedback
- Touch-based navigation
- Accessibility applications
- Physical confirmation
- Environmental feedback
- Textured interfaces
5. Movement
Definition: The science of human response including reaction times, movement times, and the physical capabilities that determine how quickly and accurately humans can interact with interfaces. Subtopics/Characteristics:
- Reaction time components
- Visual stimuli response (~200ms)
- Auditory stimuli response (~150ms)
- System response time thresholds (0.1s, 1s, 10s)
- Movement time factors
- Age and fitness variations
- Fitts’ Law
- Target distance and width
- Infinite edge width
- Corner advantages
6. Sensory Interaction
Definition: How different human senses work together and influence each other’s perception, demonstrating that senses don’t operate in isolation and can create combined perceptions different from individual sensory inputs. Subtopics/Characteristics:
- McGurk effect
- Audio-visual integration
- Cross-sensory influence
- Consistency requirements
- Mismatched cue confusion
- Multi-sensory design considerations