User Interface Design Overview

User Interface Design

• The presentation covers various aspects of user interface design, including usability, efficiency, and error types.
• Usability is defined as how well users can use the system to accomplish their tasks.
• Dimensions of Usability include Learnability (L), Efficiency (E), Safety (S), Ergonomics, and Aesthetics.
• Learnability is how easy the interface is to learn and how many repetitions it takes to become proficient.
• Efficiency is the speed and quickness in completing tasks, measured by keystrokes and clicks.
• Important factors for user interface design include how users learn new user interfaces, the ability to seek help and learning by watching.

Usability Dimensions Vary in Importance

• Usability depends on the user (novice/expert) and the specific task.
• Novice users prioritize learnability, while experts prioritize efficiency.
• The importance of each dimension also depends on the task.

How We Learn a New User Interface Entry Devices

• Learning by doing: Users explore the interface to achieve their goals.
• Seeking help: Users look for assistance when encountering difficulties.
• Learning by watching: Users observe others' interactions with the user interface.

Efficiency

• Efficiency measures how fast and effectively users accomplish tasks.
• Factors are the number of keystrokes or clicks required to complete a task.

How to Improve Efficiency of Output

• Present information in easily recognizable chunks.
• Chunking depends on presentation and user's prior knowledge,
• Working memory is typically small (4±1 'chunks') and short-lived (around 10 seconds).
• Examples of applying chunking to improve efficiency are provide.

How to Improve Efficiency of Mouse

• Make frequently used targets large.
• Position targets near each other.
• Use screen corners, and edges to minimize the steering distance.

How to Improve Efficiency of History

• Offer recently-used or frequently-used options to users for choosing.

Efficiency of Autocomplete

• Minimizing typing by providing auto-completion options.

Efficiency of Aggregation

• Aggregation is an efficient way for collecting, organizing data, objects, decisions, and graphical things to improve efficiency for users.

Anticipation

• A good design places needed information and tools within easy reach, enabling efficient task completion without needing to perform additional operations or steps.

Error Types

• Error Types include slips and lapses (skilled behavior) / mistakes (rule-based or problem-solving behavior).
• Slips are execution failures; lapses are memory failures.
• Errors occur during execution of learned procedures (slips), planning processes (mistakes).
• Slips (execution), lapses (memory), and mistakes happen in planning, and execution.

Mode Errors

• Mode errors result when the same action produces different outcomes depending on the current mode.
• This can lead to confusion and errors, which may go unrecognized.

Description Errors

• Description Errors happen with inadequate or misleading information about the current state and/or available actions.
• These can lead to user frustration, incorrect decisions, and lack of trust in the system

Capture Errors

• Capture errors occur when a user's input isn't accurately recorded by the system.
• Examples include incorrect input validation or misinterpreted actions.
• These could cause wrong data to be entered, loss of user input, or unexpected system response.

Causes of Slips

• Automaticity, interference, misinterpretations, ambiguity, and fatigue also lead to slips.
• Lack of feedback, environmental factors, time pressure, memory lapses, inattention and speed/accuracy tradeoffs also lead to slips.

Error Prevention

• Safety from capture errors include avoiding habitual action sequences with identical prefixes, avoiding actions with very similar descriptions, and keeping dangerous commands away from common ones.

Confirmation Dialogs

• Confirmation dialogs ask for user verification before making crucial changes or actions, preventing accidental data loss.

Writing Error Messages

• Prevent unnecessary errors through precise language and user-friendly messages.

User Control Over Data

• Users should have control over data, being able to create, read, update, and delete data items.
• Avoid arbitrary limits on user-defined names.

Quiz

• The quiz covers the importance of multimedia, speech and command interfaces, and wearable technologies for user interfaces for foreign language information access, the critical role of the UI is for application success, and the responsibility of UI designers for ensuring accessibility of the UI.
• Difference between usability and usefulness should be stated.
• 3 advantages for graphical system should also be stated.