Human Computer Interaction Lecture 10 Interaction Paradigms

achieving goals within constraints What is design? achieving goals within constraints goals - purpose who is it for, why do they want it constraints materials, platforms, money trade-offs

for Human–Computer Interaction understand your materials understand computers limitations, capacities, tools, platforms understand people psychological, social aspects, human error and their interaction …

To err is human Accident reports .. But … Human ‘error’ is normal aircrash, industrial accident, hospital mistake enquiry … blames … ‘human error’ But … In fact not human error but human nature concrete lintel breaks because too much weight blame ‘lintel error’ ? … no – design error we know how concrete behaves under stress Human ‘error’ is normal we know how users behave under stress so design for it! Treat the user at least as well as physical materials!

The process of design what is wanted scenarios task analysis interviews Ethnography (study of cultures) what is there vs. what is wanted guidelines principles dialogue notations precise specification architectures documentation help evaluation heuristics scenarios task analysis what is wanted analysis design implement and deploy prototype

Requirements what is there and what is wanted … Analysis ordering and understanding Design what to do and how to decide Iteration and prototyping getting it right … and finding what is really needed! Implementation and deployment making it and getting it out there

How to design with focus on users? know your user Personae (character) User Focus Designing systems with focus on user is called User-Centred Design. How to design with focus on users? know your user Personae (character)

Know your USER who are they? probably not like you! talk to them Harder to answer if you are designing a generic software like word processor probably not like you! You assume your own interests and abilities talk to them Structured interviews, open-ended discussions Bringing potential users fully into the design process - Participatory design

know your user watch them Talking with people might not be enough Think about walking Solution: watch and observe them either informally or involving them Observations tell you what they do, they will tell you why

know your user use your imagination Observing users can be costly … imagine their experiences

Persona Picture of an imaginary person who represents your core user group description of an ‘example’ user not necessarily a real person use as substitute user what would Betty (as a Warehouse manager) think

Scenarios stories for design use and reuse

scenarios stories for design or stories of interaction linearity Example of a short scenerio: User intends to press the “save” button, but accidentally presses the “quit” button, so looses his work communicate with others (Designers, users) validate other models understand dynamics (Behaviour of system not only screen shot) linearity time is linear - our lives are linear

Navigation Design Local structure – single screen(control) Global structure – whole(system) site

From one screen looking out Local Structure From one screen looking out

Four golden rules knowing where you are knowing what you can do knowing where you are going or what will happen knowing where you’ve been or what you’ve done

Where you are – breadcrumbs shows path through web site hierarchy -Category, subcategory , this page

Design Focus- modes lock to prevent accidental use … remove lock - ‘c’ + ‘yes’ to confirm frequent practiced action if lock forgotten in pocket ‘yes’ gets pressed goes to phone book in phone book … ‘c’ – delete entry ‘yes’ – confirm … oops !

Global Structure between screens within the application

Hierarchical Diagrams the system info and help management messages add user remove user

Network Diagrams main screen remove user confirm add user show different paths through system

Levels of Interaction Widget choice Menus etc. Form Elements, tag, links Buttons, dials, lights Screen design, Page design Application navigation, Site Structure Environment other apps, O/S ,Web browser, The real world