Fitts' Law and Human-Computer Interaction

Discovery Phase

• Involves understanding the work people do and the challenges they face
• Includes techniques such as interviews, focus groups, reading corporate documentation, logging activities, and questionnaires
• Important to partner with users and be aware of the Hawthorne effect

Requirements Collection Phase

• Formally identifies the people involved, things used, processes involved, constraints, inputs, and outputs
• Models information by creating descriptions of users, documenting main use-cases, and creating stories or diagrams

Ideation

• Involves generating ideas and proposals for the design
• Can be done through visualizing ideas through sketching, brainstorming, and critiquing
• Iterative process that loops back frequently
• Key factors include work roles, personas, models, task structure, and requirements

Wicked Problems

• Messy issues with no single good answer and no easy way to optimize or resolve the problem
• Examples include Microsoft's Start button and macOS menu bar

Fitts' Law

• Describes the time taken to move a pointer to a target
• Formula: T = a + b log2 (D / W)
• Factors include the distance to move the pointer, target width, and user-dependent constants
• "Index of difficulty" is the logarithmic component of the formula
• Helpful in informing design decisions such as button placement, dropdown lists, and target sizes

Contextual Inquiry

• Focuses on figuring out what users require from the system
• Involves observing users' work practices to understand their goals, practices, and domain
• Allows for designing a good system that meets users' needs

Visual Design

• Influenced by human perception and interpretation of visual information
• Gestalt principles of perception include:
  • Proximity principle: objects closer together are seen as belonging together
  • Closure principle: we see things as complete objects, even if there are gaps
  • Similarity principle: objects with similar visual characteristics are seen as a group
  • Area principle: objects with small area tend to be seen as the figure
  • Common fate principle: objects that move together are seen as related
  • Symmetry principle: symmetrical figures tend to be seen as complete figures
  • Continuity principle: we see things as continuous, smooth representations
  • Surroundedness principle: an area surrounded will be seen as the figure
  • Prägnanz principle: we tend to perceive things based on the simplest interpretation

Interaction Design and Prototyping

• Interaction design accounts for how users interact with devices and formats
• Prototyping involves creating in-progress displays of the final product for feedback and iteration
• Prototypes can be low-fidelity, such as storyboards or sketches, or high-fidelity, such as a limited piece of software
• Important considerations for visual interaction design include:
  • Look and feel of the system
  • Friendliness and playfulness
  • Motion and animations to support perception and understanding
  • Gestures and intuitiveness

Learn about Fitts' Law, a fundamental principle in human-computer interaction that predicts the time required to move a pointer to a target. Understand the formula and its significance in user interface design.