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CSCD 487/587Human Computer Interface
Winter 2013
Lecture 3HCI and Interactive Design
Introduction
Last time …
–Defined “Interaction Design”• Designing interactive products to support
the way people communicate and interact in their everyday and working lives
• Looked at some Good and Bad designs
• Learned about history of user interfaces including people who created some early interface products
Good
BadUgly
Today's Overview
•What is Interaction Design?—Four basic activities
—Three key characteristics
•Some practical issues—Who are the users?—What are ‘needs’?—Where do alternatives come from?
—How do you choose among alternatives?—Some general guidelines
What is Interaction Design?
•It is a process—Goal-directed problem solving activity informed by
• Intended use,• Target domain,• Materials,• Cost, and feasibility• And, FORMOST - USERS
—Creative activity
Four basic activities
There are four basic activities in Interaction Design
1. Identifying needs and establishing requirements2. Developing alternative designs3. Building interactive versions of the designs4. Evaluating those designs
Three key characteristics
Three key characteristics permeate these four activities1. Focus on users early in design2. Identify, document and agree to specific
usability and user experience goals3. Iteration is inevitable. Designers never get it right first time !!!
Some practical issues
•Who are the users?
•What are their ‘needs’?
•Where do alternatives come from?
•How do you choose among alternatives?
Who are the users?
•Not as obvious as you think—Those who interact directly with the product—Those who manage direct users—Those who receive output from the product —Those who make the purchasing decision
User Categories
Three Categories of User Primary Frequent hands-on Secondary Occasional Tertiary Affected by its introduction, or will influence its purchase
Wider term: Stakeholders
Who are the stakeholders?
Check-out operators
CustomersManagers and owners
• Suppliers• Local shop owners
Grocery check-out System
Who are the users? • What are their capabilities? Humans vary in many dimensions!
• Some Examples— Size of hands may affect the size and positioning of input buttons— Motor abilities may affect the suitability of certain input and output devices — Height if designing a physical kiosk — Strength - a child’s toy requires little strength to operate, but greater strength tochange batteries
What are ‘needs’?•Do you agree with these statements?•Users rarely know what is possible•Users can’t tell you what they ‘need’ to help them achieve their goals
•Instead, look at existing tasks—Their context—What information do they require?—Who collaborates to achieve the task?—Why is the task achieved the way it is?
Where do alternatives come from?•Humans stick to what they know works
• But considering alternatives is important to ‘break out of the box’
•Designers are trained to consider alternatives• Software people generally are not
•How do you generate alternatives?—‘Flair and creativity’: Research & synthesis —Seek inspiration: Look at similar products or look at very different products
Or
Or
How do you choose among
alternatives?• Evaluation with users or with peers e.g. prototypes• Technical feasibility: Some not possible• Quality thresholds: Usability goals lead to usability CriteriaCan use these to help decide on correct design
Look at what exactly are Usability Goals ...
Usability Goals
• Look at usability goals to help determine best choice among possible designs
• What is usability in general?• Usability refers to ensuring that interactive products are easy to learn, effective to use, and enjoyable from the user's perspective.
Usability Goals
• Usability can be broken down into the following goals
• Effectiveness• Efficiency• Safety• Utility• Learnability• Memorability
Usability
Effectiveness Goodness of the product in meeting
its intended use Efficiency
Way product supports users in carrying out their tasks
Safety Protecting users from dangerous
conditions or undesirable conditions
Usability
Utility Refers to extent to which product
provides right kind of functionality so that users can do what they need to do
Example: Tax program that lets accountants do tax returns
Learnability How easy is a program to learn to use
Usability
Memorability How easy a program is to remember
how to use once learned These goals can transformed into
usability criteria Not all of these will be relevant to each
product!!
User Experience Goals
User experiences are somewhat objective and concerned with how a system feels to users
Two sides to describing user experiences
Desirable aspects and undesirable aspects
User Experience Goals
Desirable Program Aspects Satisfying, enjoyable, engaging,
pleasurable, exciting, entertaining, helpful, motivating, challenging, fun, provocative, surprising, rewarding
Undesirable Program Aspects Boring, frustrating, annoying,
childish, unpleasant, patronizing, cutesy, making you feel stupid
Principles of Design
Design Principles Used by designers to aid them in
designing the user experience Concerned with what users should
see and do when carrying out tasks Most common are:
Visibility, Feedback, Constraints, Consistency and Affordance
Principles of Design
Visibility The more visible functions are, the
more likely users will know what to do next
And, when functions are out of sight, more difficult to find them and know how to control them
Example: Sensor based lights
Principles of Design
Feedback Involves sending back information
about what action has been done And what has been accomplished Examples: Audio, visual, verbal, and
combinations
Principles of Design
Constraints Restricting kinds of user interaction
that can take place at a given moment Example: Greying out certain menu
choices Consistency
Design so interface has similar interactions for similar tasks
Example: Using mouse clicks for similar tasks
Principles of Design
Affordance Attribute of an object that allows
people to know how to use it Afford means to “give a clue” Example: Door handles, scissors,
hammer
Summary
Process of Interaction design is a four step process
Identifying needs and establishing requirements
Developing alternative designs Building interactive versions of the designs Evaluating those designs Usability Goals contribute to the process User experience goals also contribute to the
design process Common design principles should also be included
in and Interactive design process
The End
Reading
– Chapter 1 .. moving on to Chapter 2
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