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Week 4. Thossaporn Thossansin . BS.c , MS.c. Usability: User Needs Analysis. e-mail: thossaporn.piu@gmail.com. Introduction User Interface Design GUI building blocks GUI structures Usability Good design / bad design Usability levels User-centered design Principles and ideals
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Week 4 ThossapornThossansin. BS.c, MS.c Usability: User Needs Analysis e-mail: thossaporn.piu@gmail.com
Introduction User Interface Design GUI building blocks GUI structures Usability Good design / bad design Usability levels User-centered design Principles and ideals The process Agenda
ISO 9241 usability definition What is Usability? The effectiveness, efficiency, and satisfaction with which specified users can achieve specified goals in particular environments.
Why is Usability Important? • The fate of • the world 2. The Apple iPhone
Bush won Florida by a 537-vote margin in official results The Fate of the World The 2001 Florida Ballot Incident
5,330 Palm Beach County residents invalidated their ballots by punching for Gore and Reform Party candidate Pat Buchanan. Almost half of them were 65 or older and Democrats. The Florida Ballot
We design the user interface here We test them here Usability vs. Specification Initiation Requirement Specification Design Implementation Is it too late? Testing
Therefore, we need a crush course in: UI Design Usability principles User-centered design Note, these issues will be discussed in a very shallow manner. Each of these issues deserve a course Specification Design Implementation Testing User Centered Design Initiation Requirement UI Design + Testing
Introduction User interface design GUI building blocks GUI structures Usability Good design / bad design Usability levels User-centered design Principles and ideals The process Agenda
Basic Model of HCI Computation input Computer output
Types of User Interfaces Graphical User Interface (GUI) Command Line Voice activated interfaces
GUI Model input Computation Keyboard : {I{A..Z, 1..0,...}} Mouse : {x0..1024, y0..768} Computer output Screen : {(x,y)Z2}
What is the type of information received by each input field? What’s the effect? GUI Components: Simple Input Text field Button Text area Link
What is the difference between a radio button and a check box? What is the choice domain and the choice range of each component? Simple GUI components: Choosers Combo box Slider Checkbox Radio button
Larger Constructs Pages (in Web-based systems) Windows (in Desktop-based systems)
Composing components Tabs Areas of reference List
Actions Task Context Consequences
User flow: take the user aspect with the use-case model Storyboard: Find compositions of actions / information Find relations between compositions Detailed view: Refine each composition to the component level Check and integrate Designing Interface Elements (top-down) Use Case
Integrate use-case scenarios from the user perspective User flow
Introduction User interface design GUI building blocks GUI structures Usability Good design / bad design Usability levels User-centered design Principles and ideals The process Agenda
What makes a good design different from a bad design? In order to answer this question we will define the concept of usability. Good UI design vs. bad design
Recognizable Simple Clear purpose Learnable Safe Flexible Robust Good Metaphors ... Good design
Recognizable interfaces Pretty, or smart, is not necessarily Usable
Design patterns in HCI are a good way to explore suggestions for good design We would look at some patterns: Wizard (for simplicity) Contextual help (for learnable interface) Go back to a safe place Shortcuts (for flexible) Undo (for robustness) Patterns
Problem: The user wants to achieve a single goal but several decisions need to be made. Solution: Take the user through the entire task one step at the time. Wizard
Problem: Users may need help regarding specific tasks, but would spend a lot of energy searching for it. Solution: Place help in the context of the given task. Contextual Help
Computers can be SCARY Sometimes an innocent user gets into a state she don’t want to be in… And then, the terror!!!
Provide a way to go back to a checkpoint of the user's choice. Solution The "Home" button and the “Back” Clicking the Logo in Web sites
Problem: Power users need faster ways to execute operations than novice users Solution: Create shortcuts for power operations, using keyboard, combinations, icons, special menus etc... Shortcuts
Problem: The user might regret executing some operation. Asking the user for confirmation after executing each operation will make the interaction unusable. Solution: Enable the user to undo her operations, after they were executed. Undo
Usability levels Component Application Project
Familiar to use Gives feedback Reduces errors Satisfies a given task Readable Self explaining Component Level
Accessible Gives sense of place Easy to navigate in Handles errors Realistic Scenarios Personalized Application Level
Answers real needs Answers current needs Generates value Communicate with all organization's units Project Level
Introduction User interface design GUI building blocks GUI structures Usability Good design / bad design Usability levels User-centered design Principles and ideals The process Agenda
The objective is to create a design process that would increase the usability of the product Three principles: Finding the user’s context of the product Iterative process, including ongoing tests and revisions Participatory Design - Users become members of the design team User Centered Design Initiation UCD: User is involved here Requirement Specification Design Implementation Classic: User is involved here Testing
Requirements gathering stage: Talk / view users Identifying personas Specification stage: Interface prototyping Usability expert analysis Heuristic Evaluation Design / Implementation Usability Lab Log Analysis Where are the differences
Talk to users Interview them in order to discover user’s culture, requirements, expectations, etc. Watch the users At work See how they use their existing systems See what they do not use Requirements stage
Personas are hypothetical archetypes of actual users By identifying a small set of personas, we can: make the users seem more real Judge the importance of features Look at the: Usage frequency Competency ... Identifying Personas Taken from http://www.w3.org/WAI/redesign/personas
Brainstorm Rough interface design Application walkthrough Prototyping Specification Low fidelity paper prototypes
Fine tune interface design Screen design Heuristic evaluation and redesign Prototyping – Intermediate Stages Design Medium fidelity prototypes