] User-Centered Interface Design and Development

User-Centered Interface Design and Development

-- Chapter 1: Introduction --

Franz Kurfess
Chapter Overview
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  • good vs. bad design

  • interaction design

  • interaction design process

  • goals of interaction design

  • design and usability principles

What is Interaction Design?
  • interactive products

  • interactive systems

  • design emphasis on the system

  • design emphasis on the user

  • What is Interaction Design?
    • Interactive Products
    • Interactive Systems
  • Good vs. Bad Design
  • Poor Design Makes Users Unhappy
  • What is Interaction Design?
  • Interaction Design Process
  • Goals of Interaction Design
  • Design and Usability Principles
Interactive Products
    • intended for a relatively narrow taks

    • functionality exposed to the user is relatively low

  • Examples

    • TV

    • phone

    • coffee maker

    • door

    • computer mouse

Interactive Systems
    • intended for a a wide range of taks

    • user has to deal with complex functionality

    • computer

    • car

    • entertainment system (stereo)

    • espresso machine

Good vs. Bad Design
  • emphasis is on user experience

  • tensions between various factors

  • Good vs. Bad Design
    • Good Design Makes Users Happy
    • Product Analysis Activity
  • Poor Design Makes Users Unhappy
  • What is Interaction Design?
  • Interaction Design Process
  • Goals of Interaction Design
  • Design and Usability Principles
Good Design Makes Users Happy
    • product performs its task

    • satisfactory, enjoyable user experience

    • functionality and performance are critical (within limits)

    • the outcome of the task should match or exceed the user's expectations

    • performing the task and using the product should be easy

    • unexpected events should distract as little as possible

    • users with different capabilities should be accommodated

Product Analysis Activity

Scenario: Assume your grandmother is going on a long roadtrip involving a long stretch of road in an unpopulated area. From a usability perspective, is it better for her to have a cell phone with her, or would you rather explain to her how the road-side emergency phones work?

  • aspects to consider

    • functionality: what are the most important tasks

    • performance: how good are the products at those tasks

    • capabilities and background of the user

    • environment: external factors that influence the user experience

Poor Design Makes Users Unhappy
  • lack of functionality or poor performance

  • difficulty in obtaining a desired result

  • actions achieve unexpected results

  • product is difficult to handle

  • appearence of the product is unpleasant

  • Poor Design Makes Users Unhappy
    • Functionality and Performance
    • Achieving Results
    • Unexpected Outcomes
    • Product Handling
    • Appearance
  • What is Interaction Design?
  • Interaction Design Process
  • Goals of Interaction Design
  • Design and Usability Principles
Functionality and Performance
    • critcal aspects of many products

    • designers are often aware of them

    • often conscious decisions to sacrifice them because of other important aspects (cost, safety, manufacturing)

    • these aspects are in the focus of designes and engineers

    • sometimes designers are not aware of the importance users place on certain functionality and performance criteria

    • the product may be used for unexpected tasks or in unintended ways

    • the product is targeted at the wrong user group

Achieving Results
    • using a product for its intended task is not always obvious for most users

    • task familiarity

    • user background

    • environment

    • since the designer spent a lot of time working on the product, it is obvious to them how to use it

    • especially difficult for tasks the user is not very familiar with

    • user limitations (focus, ergonomics)

    • (perceived) urgency or danger can cause stress

    • aspects of the environment (e.g. movement, noise) can add to difficulties

Unexpected Outcomes
    • an interaction with the product does not produce the expected result

    • beyond the parameters the user considers for performance and functionality

    • may lead to confusion or worse consequences

    • inconsistent outcomes are especially bad

    • "you should have read the manual" is not enough

    • if possible, products should be designed to prevent bad outcomes in addition to enabling good ones

Product Handling
    • manipulation of interaction mechanisms

    • makes use of the "affordances" of a product

    • touching and experiencing physical aspects of the product while it is being used

    • affordances are the "natural" or "obvious" interaction mechanisms with a product

    • physical interactions with the product have a significant impact on user experience

    • users may have difficulties explaining why they like or dislike the way a product "feels"

    • ergonomics deals with such issues

    • can be especially challenging for engineers

Appearance
    • sensory percepts relayed by the product

    • most often looks, sometimes sound, touch, smell

    • appearance may not be relevant for functionality or performance

    • it can be an important criterion for users to distinguish "good" from "poor" design

    • sometimes design is used as a synonym for appearance (not in this class)

    • can also be a major challenge for engineers

    • may depend on fashion ("fad")

What is Interaction Design?
  • definition

  • contributing disciplines

  • applications

  • What is Interaction Design?
    • Definition of Interaction Design
    • Driving Forces
    • Contributing Disciplines
    • Related Interdisciplinary Fields
    • Design Practices
  • Interaction Design Process
  • Goals of Interaction Design
  • Design and Usability Principles
Definition of Interaction Design

Designing interactive products to support people in their everyday and working lives [Preece, Rogers, and Sharp, 2002].

    • emphasis on support of people, not on highest functionality or performance

    • includes professional and personal activities

Driving Forces
    • before computers were widely used, most complex systems were designed by engineers for engineers

    • now, many devices perform complex tasks for regular users

    • often it is unrealistic to expect users to spend a lot of energy on learning how to use products

    • functionality and performance used to be more important as distinguishing factors, but that is changing for more and more products

    • our professional and personal lives are becoming inundated with products that perform complex tasks

    • some of these products may affect critical aspects like health, security, privacy

    • poor design should not have to be overcome by forcing the user to adapt to the product

Contributing Disciplines
  • ergonomics

  • cognitive science, psychology

  • informatics

  • computer science

  • software engineering

  • social sciences

Related Interdisciplinary Fields
  • human-computer interaction

  • human factors

  • cognitive engineering

  • cognitive ergonomics

  • information systems

  • computer-supported cooperative work

  • computer modeling

  • virtual reality

Design Practices
  • product design

  • graphic design

  • industrial design

  • artist-design

  • photography

  • film industry

Interaction Design Process
  • Interaction Design Process
  • Goals of Interaction Design
  • Design and Usability Principles
Goals of Interaction Design
  • Goals of Interaction Design
  • Design and Usability Principles
Design and Usability Principles
  • Design and Usability Principles
Chapter Summary

table of contents

User-Centered Interface Design and Development
  1. Chapter Overview
  2. What is Interaction Design?
    1. Interactive Products
    2. Interactive Systems
  3. Good vs. Bad Design
    1. Good Design Makes Users Happy
    2. Product Analysis Activity
  4. Poor Design Makes Users Unhappy
    1. Functionality and Performance
    2. Achieving Results
    3. Unexpected Outcomes
    4. Product Handling
    5. Appearance
  5. What is Interaction Design?
    1. Definition of Interaction Design
    2. Driving Forces
    3. Contributing Disciplines
    4. Related Interdisciplinary Fields
    5. Design Practices
  6. Interaction Design Process
  7. Goals of Interaction Design
  8. Design and Usability Principles
  9. Chapter Summary