Human-Computer Interaction Overview ● Benefits of more usable Websites ● History of HCI ● Goals of HCI ● User-Centered Methodology

Have you ever: ● been unable to find something in a website that you know is there? ● recevied a useless or misleading error message? ● wondered why a website needs to know your e- mail address? ● left a site for fear information you provided might be misused?

It should not be that way ● Websites can be designed to be: – Pleasant & convenient for users. – where users can acomplish their goals. ● The Key is to think about users – Learn about them – Observe them – Interview them

Benefits of usable Websites ● Gaining a competitive edge ● Reducing development/maintenance costs ● Improving user productivity ● Lowering support costs

Gaining a competitive edge ● Number of hits to a site vs conversion rate – Number of hits only counts visitos not sales – Conversion rate is the percentage of visitors who take an action you want them to take – Higher conversion rates leads to lower sales cost – Most significant factor in higher conversion rate is the ease of use – Average conversion rates were 3.2% in 2003

Reducing development/maintenance costs Learn about users first to avoid: ● Implementing features that users do not want. ● Features that are annoying or inefficient. ● Making changes late in the development cycle (high cost). ● Lower life-cycle maintenance cost. ● Most maintenance costs come from unmet or unforeseen user needs

Improving User Productivity ● e-commerce: users find what they want—and succeed in buying it ● company intranet: employees become more efficient

Lowering support costs ● Calls to costumer support are very expensive ● Average service call is $12 to $250 ● Wall-Mart shut down shopping site for three weeks (1999) ● Customer confusion affecting support systems ● A Website that reduces support calls can result in tremendous savings

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.” ● Special Interest Group on Human-Computer Interaction (SIGCHI) of the Association for Computing Machinery (ACM)

Interactive Computing Systems Examples: ● A PC used for Web browsing: e-commerce, database ● Embedded devices: automobiles, planes ● Handheld devices: cells phones, GPS, Palm pilots, etc. ● Software for multi-user collaboration

Computing Cost Shift 40 year ago: cost of one computer = salary of 200 programmers today: salary of one programmer = cost of 200 computers Now: goal is to make computers easy to use, to save user time

How to make computers easy to use? ● Applying principles of Human-Computer Interaction – Consider physical limitations – Consider the environment where it is located ● By being and advocate of the user – an HCI practitioner listens to the users and communicates with the development team

Goals of HCI Develop or improve: – Safety – Utility – Effectiveness – Efficiency – Usability – Appeal... of interactive systems that involve computers

Safety ● Safety of Users – Air traffic control – Hospital intensive care – Hospital radiation unit ● Safety of Data – Protection of files from tampering – Privacy and security

Utility ● what services a system provides: – Information – Instruction – Purchases – Banking transactions – Investing – Etc.

Effectiveness ● User’s ability to achieve goals: – Find desired information – Enter credit card data – Arange a payment – Able to upload a class assignment ● A web site might provide all necessary services, but if users can’t find the items they want to buy, the site lacks effectiveness

Efficiency ● Measures how quickly users can accomplish their goals using the system

Usability ● Ease of learning ● Ease of use

Appeal ● How well users like the system – First impressions – Long-term satisfaction