Lecture 2: Usability, HCI and User-Centered Design Methodology Lecture prepared for Interface Design DMS 546/DMS 446 This lecture is based on chapters 1 and 3 of User-Centered Website Development (McCracken and Wolfe), chapter 1 of Designing Web Usability (Jakob Nielsen), “Human-Computer Interaction and Your Site” (Nicky Danino - http://www.sitepoint.com/article/computer-interaction-site ), on a Powerpoint presentation at http://www.vtc.edu.hk/ive/ty/ict/ , a Powerpoint presentation by Franz J. Kurfess at http://users.csc.calpoly.edu/~fkurfess/Courses/484/W07/Slides and slides provided with Interaction Design (Preece, Rogers, Sharp)
Transcript
Lecture 2: Usability, HCI and User-Centered Design Methodology
Lecture prepared for Interface Design DMS 546/DMS 446
This lecture is based on chapters 1 and 3 of User-Centered Website Development (McCracken and Wolfe), chapter 1 of Designing Web Usability (Jakob Nielsen), “Human-Computer Interaction and Your Site” (Nicky Danino - http://www.sitepoint.com/article/computer-interaction-site), on a Powerpoint presentation at http://www.vtc.edu.hk/ive/ty/ict/, a Powerpoint presentation by Franz J. Kurfess at http://users.csc.calpoly.edu/~fkurfess/Courses/484/W07/Slides and slides provided with Interaction Design (Preece, Rogers, Sharp)
creating features that are annoying or inefficient
high cost of making changes late in the development cycle
Improved productivity
Shopping site:
customers are able to buy easier
Intranet or custom software solution:
employees are able to be more efficient
Lower support costs
calls to customer support can cost the company $12 to $100 or more per call
avoid user problems by making the site more usable
HCI Origins
HCI Origins
Scenario:
$3,000,000 mainframe computer (1966)compared to the cost of the computer, salaries
are cheap. Therefore train an expert to operate the computer. Relatively few computer operators are needed.
HCI Origins
But with the expanding computer market(IBM Personal Computer for home and small
business released in 1981...) cheaper computers are operated by people who are not technicians or computer scientists.
HCI Origins
ease of use becomes an issue
industry needs to find ways to make the computer usable by a broad market
HCI Origins
HCI has roots in
Human Factors (machinery operation - origins in WWII-era aviation)
ergonomics (usually more associated with workplace and repetitive tasks)
What is HCI?
“Human Computer Interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of the major phenomena surrounding them.” (ACM SIGCHI working definition)
Goals of HCI
To develop or improve the
Safety
Utility
Effectiveness
Efficiency
Usability
Appeal
. . . of systems that include computers
Safety
safety of users, safety of data (or both)
Utility
services the system provides
information
instruction
purchases
etc.
Effectiveness
User's ability to use the services:
find desired information
enter credit card data
etc.
Efficiency
How quickly users can accomplish goals or finish work using the system
Usability
ease of learning
ease of use
Appeal
How well users like the system
first impressions
long-term satisfaction
Design Process Overview
Design Process Overview
Need to take into account:Who the users areWhat activities are being carried outWhere the interaction is taking place
Need to optimise the interactions users have with a product
Such that they match the users activities and needs
Design Process OverviewUnderstanding users’ needs
Need to take into account what people are good and bad at
Consider what might help people in the way they currently do things
Listen to what people want and get them involved
Use tried and tested user-based methods
Design Process OverviewWhat is involved in the process of HCI design?
Identify needs and establish requirements
Develop alternative designs
Build interactive prototypes that can be communicated and assessed
Evaluate what is being built throughout the process
Design Process OverviewCore characteristics of interaction design
users should be involved through the development of the project
specific usability and user experience goals need to be identified, clearly documented and agreed at the beginning of the project
iteration is needed through the core activities
User-Centered Development
User-Centered Development
Characteristics of User-Centered Development:
iterative process
Design -> Prototype -> Evaluate if it passes evaluation of usability specifications, it is ready to implement
if it fails, then repeat the Design -> Prototype -> Evaluate process
User-Centered Development
Needs AnalysisUser and Task AnalysisFunctional AnalysisRequirements AnalysisSetting Usability SpecificationsDesignPrototypingEvaluation
User-Centered Development
Needs Analysis
A few sentences summarizing nature and purpose of the proposed system.
User-Centered Development
Needs Analysis
example: “The redesigned website for the Plains Art Council
in Burkmere, SD will foster greater participation in the arts in the local community by providing a comprehensive listing of available art programs and services and by creating an online gallery for local artists.”
Q: who is the audience for this site?
User-Centered Development
User and Task Analysis
User Analysis characterizes the people who will use your site.
age, education, familiarity with computers,
experience or expectations with similar software or sites
User-Centered Development
User and Task AnalysisTask Analysis looks at what the users will want
to accomplish using the software or site goals:
buy shoescommunicate with friends
specific tasks:search, view images, compare prices, purchase send and receive messages, upload and view photos, etc
User-Centered Development
Functional AnalysisThe computer services that will be needed for the tasks.
search and sort capability
“shopping cart,” secure credit card transaction
at this stage – make decisions about how much functionality to build (could just put a telephone number instead of online reservation, etc.)
User-Centered Development
Requirements AnalysisFormal specifications...
may include:Data DictionariesEntity Relationship DiagramsObject-Oriented Modelling
User-Centered Development
Setting Usability Specifications
performance measures
preference measures
User-Centered Development
Setting Usability Specificationsperformance measures are directly observable
examples:time to fill out billing an shipping informationnumber of clicks to locate what is playing at a specific movie theater# of tasks completed correctly / # of errorshow many times did user need to type additional info on a form? # of negative comments or facial expressions(?)what parts of the screen the user looked at (eyetracking)
