An Introduction to User Interface Design Balaji Rajagopalan

Outline l User Interface Defined l Models of Interface Design l Principles

User Interface Defined “It's simply the parts of a computer and its software that you (the computer user) see, hear, touch, or talk to. It is the set of all the things that allow you and your computer to communicate with each other. ” (Source: IBM Design Concepts)

“The best user interfaces are the ones you don't have to pay much attention to” (Source: IBM)

Three models during user interface design l l l The user's conceptual model represents what the user thinks is happening and why The user interface designer's model describes what the user is intended to experience The programmer's model describes implementation details

User's conceptual model l l Just as an architect must understand a client's needs and expectations to design a house that pleases the client, the user interface designer needs to understand users, their tasks, and their expectations. The key is to start UI early in the design cycle.

Understanding User Needs l l l using resources such as task analysis, surveys, customer visits, and user requirements lists incorporating information that users provide into the user interface design conducting usability tests (Project groups with an emphasis on UID will carryout all of the above)

Simplicity, a golden rule “Man is an over-complicated organism. If he is doomed to extinction he will die out for want of simplicity” - Erza Pound

First law of interface design “A computer shall not harm your work or, through inaction, allow your work to come to harm” e. g. , Accept-Reject feature and Save

Second law of interface design “A system shall not waste your time or require you to do more work than is strictly necessary” l SAIL system will make sure you work hard! l l State – Selection of Term & CRN selection – Say What?

User Interface Design Pattern

Top Web-Design Mistake of 2002 1. No Prices l “No B 2 C ecommerce site would make this mistake, but it's rife in B 2 B, where most "enterprise solutions" are presented so that you can't tell whether they are suited for 100 people or 100, 000 people. Price is the most specific piece of info customers use to understand the nature of an offering, and not providing it makes people feel lost and reduces their understanding of a product line. We have miles of videotape of users asking "Where's the price? " while tearing their hair out. ” Source: Jakob Nielson’s Useit. com

Good Interface Design requires… Thinking early in the design process l Understanding human learning and performance And doesn’t come easy… l A good user interface rarely happens on the first try. Build time into your schedule to iterate your design. Each time find out what worked and what did not work. Pick out the trouble spots and work through them. A good interface takes time. Bad Interface design is easy and costly! One estimate puts loss of revenue at about $20 B owing to poor interface design

Coming up… l Cognetics and the locus of Attention l Meanings, Modes, Monotony, and Myths