Human-Computer Interaction Concepts

A comprehensive set of vocabulary flashcards focusing on Human-Computer Interaction principles and concepts.

Human Action Cycle

Sequence: goal → intention → specify actions → execute → perceive → interpret → evaluate. separates execution vs evaluation; design should minimize gaps.

Purpose of Controls

Allow user to perform actions to achieve goals. Good design: actions are visible, easy, and safe.

Purpose of Displays

Provide information about system state. Good design: relevant, legible, understandable.

Information Theory

Information reduces uncertainty (measured in bits). In HCI, displays reduce uncertainty about system state.

Hick-Hyman Law

More choices increase decision time due to cognitive processing load. Design should reduce options and group logically.

Hick-Hyman Implication

Fewer, clearer options improve speed and reduce errors.

Fitts’ Law

Movement time increases with distance and decreases with target size.

Fitts’ Law Implication

Make buttons large and close to reduce movement time and errors.

Working Memory

Limited capacity system for temporary information processing.

Long-Term Memory

Stores knowledge and experience for later use.

Display Categories

Alerting, monitoring, integrating, navigation, data visualization.

Control Categories

Discrete (buttons), continuous (tracking), input (keyboard).

Alert Levels

Advisory (low), caution (medium), warning (high urgency).

Advisory Alerts

Low urgency; typically visual to indicate status.

Caution Alerts

Moderate urgency; often include auditory signals.

Warning Alerts

High urgency; high salience to demand attention.

Legibility

Ease of reading; affected by contrast and size.

Discriminability

Ability to distinguish between items.

Meaningfulness

Match between symbol and user understanding.

Proximity Principle

Place labels near associated items.

Icons

Visual symbols best for persistent system states.

Earcons

Auditory signals best for time-based events.

Monitoring Displays

Used to track changing system states.

Set Task

User sets a value (e.g., thermostat).

Watch Task

User observes system (e.g., monitor).

Track Task

User follows changing values (e.g., aircraft display).

Analog Display

Continuous representation; good for trends.

Digital Display

Discrete numeric values; good for precision.

Analog Advantage

Shows rate of change and supports mental models.

Digital Advantage

Precise and quick to read exact values.

When Analog is Better

When detecting trends or changes over time.

When Digital is Better

When exact values are required.

Key Design Factors

Rate of change, precision, and range.

Primary Visual Area (PVA)

Area where user focuses most attention.

PVA Rule

Place important and frequent info near PVA.

Clutter Avoidance

Separate unrelated info to reduce overload.

Grouping Principle

Group related elements to aid attention.

Control-Display Compatibility

Controls should match display layout and function.

Configural Displays

Combine multiple variables into one visual pattern.

Benefit of Configural Displays

Reduce mental workload through pattern recognition.

Ecological Interface Design

Visualize system constraints to aid decisions.

Phase-Related Displays

Change based on task stage.

Risk of Phase Displays

Too many modes cause confusion.

Head-Up Displays (HUD)

Overlay info in user’s view to reduce attention shifts.

HUD Risk

Clutter and distraction.

Head-Mounted Displays (HMD)

VR/AR displays attached to head.

HMD Issues

Lag, discomfort, misalignment.

Pursuit Display

Shows both input and system output.

Pursuit Advantage

Allows prediction of disturbances.

Compensatory Display

Shows only error relative to target.

Compensatory Advantage

Simpler when prediction is not possible.

Navigation Tasks

Direct, plan, reorient, track.

Route Lists

Static directions that do not update.

Command Displays

Dynamic navigation instructions.

Map Legibility

Requires good contrast and readable labels.

You Are Here

Helps orientation on maps.

Map Orientation

Should minimize need for mental rotation.

Map Scale

Allows zooming for detail or overview.

2D Maps

Best for precision tasks like driving.

3D Maps

Best for terrain understanding.

Tables

Provide precise numerical values.

Graphs

Show trends and relationships.

Scatterplot

Shows relationships between variables.

Histogram

Shows distribution of data.

Timeline

Shows change over time.

Box Plot

Compares distributions.

Network Diagram

Shows connections.

Dendrogram

Shows hierarchy.

Interval Data

Numeric values with meaningful differences.

Ordinal Data

Ranked categories.

Nominal Data

Categories without order.

Position Encoding

Most accurate visual representation.

Color Encoding

Best for categorical (nominal) data.

Color Rule

Use fewer than 7 colors.

Feedback

Confirms system response to action.

Feedback Importance

Prevents user uncertainty and errors.

Button Size

Small buttons increase errors (Fitts’ Law).

Redundancy Gain

Use multiple cues to improve recognition.

Labeling

Reduces confusion and training needs.

Blind Operation

Allows control without vision via touch.

Numeric Keypad

3x3 layout reduces movement time.

QWERTY

Historical design from typewriters.

Dvorak

More efficient key placement.

Chording Keyboard

Multiple keys pressed simultaneously.

Chording Advantage

Faster with practice, less movement.

Voice Benefit

Hands-free, natural interaction.

Voice Limitation

Affected by noise and variability.

Vocabulary Issue

Limited commands reduce flexibility.

Best Use

When hands/eyes are occupied.

Poor Use

Continuous precise control.

Open-Loop Control

No feedback; fast but error-prone.

Closed-Loop Control

Uses feedback; slower but accurate.

Bandwidth

Frequency of required corrections.

High Bandwidth

Harder task, more workload.

Zero-Order Control

Position directly controls output.

First-Order Control

Controls velocity.

Second-Order Control

Controls acceleration; hardest due to lag.

Gain

Output produced per input.

High Gain

Fast but causes overcorrection.

Low Gain

Accurate but slow.