Introduction: Human Computer Interaction

HFE 451/651Dr. GallimoreSpring 2000

References

• Developing User Interfaces Ensuring Usability through product and process. Hix & Hartman, 1993. New York: John Wiley & Sons.

• User and task analysis for interface design. Hackos & Redish, 1998. New York: John Wiley & Sons.

Introduction

• Why worry about HCI?– The user interface can make or break a software

package

– 48-100% of code for an interactive system is used to support the interface

– Want to make the product usable

– As similar products become available to consumers, products that are designed for the user will have the market advantage

How would you define usability?

• Accomplish goals effectively and efficiently. • Be perceived as usable.• Transparent to the work the user is trying to

accomplish.

Defining Usability Cont.

• Example characteristics– ease of learning

– high speed

– low error rate

– subjective satisfaction

– retention over time

– Reflect work flows that are familiar or comfortable

– support users’ learning style

– encompass a design concept (metaphor or idiom) that is familiar to the users.

– Consistency of presentation

– use language and illustrations that are familiar or easy to learn

Focus on user not technology

• Focus should be on user and goals, not what technology can do.

User Interface Design

• User interface design is an art and a science. There is no formula. There is a process, recommendations and guidelines.

Focus of book and class

• To learn the process of designing user interfaces.• The focus is not developing software that

implements the interface.

The Process

• The process is user centered• The user is considered at the beginning of the

design process• The process is iterative• The process involves testing

The Process