ch 10 - human computer interaction

User Interface (UI)

How information is displayed and how users interact with a system. Examples: keyboard, mouse, touchscreen, voice commands.

User Experience (UX)

How users feel while using the interface. Includes satisfaction, ease of use, and enjoyment.

Why is good HCI design important?

Reduce learning time, improve safety, increase efficiency, increase performance, and improve user satisfaction.

User Motivation

Mandatory users and Discretionary users.

Mandatory Users

Must use the system for work.

Discretionary Users

Choose to use it for recreation.

User Expertise

Novice, knowledgeable intermittent, and expert.

Novice

Need GUI and recognition rather than memory.

Knowledgeable Intermittent

Uses system occasionally and needs memory.

Expert

Uses frequently and can use command lines and shortcuts.

Task Structure

High structure and low structure.

High Structure

Steps are clearly defined. Example FAFSA or tax forms.

Low Structure

Flexible tasks. Example: drawing software.

Example of Command Line

DOS, coding.

Pros of Command Line

Very flexible, fast for experts.

Cons of Command Line

Requires memorization and low error tolerance.

Example of Function Keys

WordStar

Pros of Function Keys

Fast and efficient.

Cons of Function Keys

Hard to remember and not intuitive.

Example of Menu Selection

Microsoft Word ribbon

Pros of Menu Selection

Easy for beginners and prevents errors.

Cons of Menu Selection

Slower for experts and uses more screen space.

Example of Fill-in Forms

Tax forms.

Pros of Fill-in Forms

Easy to learn and familiar

Cons of Fill-in Forms

Lots of typing and more chances for mistakes.

Example of Question & Answer

Installation wizard

Pros of Question & Answer

Easy for infrequent users

Cons of Question & Answer

User has little control and must follow sequence

Example of Direct Manipulation

Dragging files

Pros of Direct Manipulation

Very intuitive and little typing

Cons of Direct Manipulation

Takes screen space and good icons can be difficult to design.

Example of Multi-touch & Gesture

iPad and Smartphones

Pros of Multi-touch & Gesture

Natural and easy to learn

Cons of Multi-touch & Gesture

Requires special hardware and can cause fatigue

Example of 3-D Navigation

VR and Flight simulators

Pros of 3-D Navigation

Realistic and easy to understand

Cons of 3-D Navigation

Expensive and difficult to develop

Example of Conversational

Siri and Alexa

Pros of Conversational

Natural and no training

Cons of Conversational

Voice recognition errors and doesn’t always understand context.

Norman’s 7 Stages of Action (1)

Form Goal

Norman’s 7 Stages of Action (2)

Form Intention

Norman’s 7 Stages of Action (3)

Select Action

Norman’s 7 Stages of Action (4)

Execute Action

Norman’s 7 Stages of Action (5)

Perceive Result

Norman’s 7 Stages of Action (6)

Interpret Result

Norman’s 7 Stages of Action (7)

Evaluate Outcome

Execution Gulf

Difficulty performing the action.

Evaluation Gulf

Difficulty understanding feedback.

Good design should

Make invisible processes visible, give immediate feedback, be consistent, and use familiar metaphors.

Skeuomorph

Makes technology resemble the real object.

Example of skeuomorph

E-reader that looks like a book.

Pro of skeuomorph

Easier to learn

Con of skeuomorph

May waste space and reduce efficiency.

Attention

Anticipate needs, highlight changes, limit distractions, and minimize information access.

Perception

Make affordances

Memory

Recognition > Recall. Be consistent.

Mental Models

Match real world, build trust, and keep design simple.

Response Selection

Good defaults and break complex tasks into simple steps.

Interaction

Immediate feedback, flexibility, and error prevention.

Design principles applied to

Dynamic graphs, websites/apps, wearable technology, and computers in cars.

HCI Evaluation Criteria

Learnability, efficiency, memorability, errors, and satisfaction.