Interaction Design

Chapter 10

The Human Action Cycle

Psychological model Describes steps users take to interact with

computer systems Use actions and tasks to achieve goals

The Human Action Cycle

Goal Formation Execution stage

– Translate goals into tasks– Planning the action sequence– Executing action sequence

Evaluation stage– Perceiving what's happening– Interpreting the outcome as per expectations– Comparing what happened with what was wanted

Human Action Cycle

Can be quick or fast

Can be broken down into smaller Human action cycles

Flexible

Differs from person to person

Goal Formation

One step

Think of a goal

Execution Stage

Involves thinking and action

Thinking– Translate goals into tasks– Planning the action sequence

Action– Executing action sequence

Evaluation stage

All thinking

Comparing expectation with result

HAC Influence on the Design Process

Predict difficulties

Changes to environment and technology

Skills and training

Explaining the System to the User

The user has to understand the UI The user uses

Prior knowledge Documentation Training

We use– Designer and User model, and the System image

Designer Model

What the designer knows

Structural and operational

Complete and clear

User Model

What the user knows

Functional

Sometimes incorrect

System Image

Communicate design to user

Contains– UI– Documentation– Training– What the user knows

UI and the User

Needs to meet the user model’s expectation

Needs to meet the functionality of the designer model

Take into account older user models

Metaphor

Technically all computer UI’s

Used to make an accurate user model

Used to unify UI

Problem’s with Metaphors

Adhering too strictly

Outside user experience

Make sure all metaphors connect

Making a metaphor

Task scenarios, use cases, requirements gathering

Make sure makes sense to user

Make several

Questions?