Scenario-Based Usability Engineering Chris North cs3724: HCI

Homework #1 Qualitative discussion Quantitative discussion Projects Usability problems, errors, access, alternate tasks, … Quantitative discussion Data averages, min, max Data visualization Statistics, t-tests, … Projects Book

Myth The user interface is tacked on at the end of the project

Newton vs. Palm Newton Palm

User Interface Metrics Ease of learning Ease of use User satisfaction Not “user friendly”

Tradeoffs Optimization? Examples Identify tradeoffs Choose based on design goals Track tradeoffs for rationale

SBD Method: Claims (see pgs 73-4) Repeated involvement by same students + increases competence + encourages community - hard to break in Competition among students for prizes + rewards time/effort increases frustration hard to compare diversity

Using “Scenarios” Stories about people and their needs, activities A problem scenario describing current situation: Marissa was not satisfied with her class today on gravitation and planetary motion. She is not certain whether smaller planets always move faster or how a larger or denser sun would alter the possibilities for solar systems. She stays after class to speak with Ms. Gould, but she isn’t able to pose these questions clearly, so Ms. Gould suggests that she re-read the text and promises more discussion tomorrow.

A design scenario describing our initial vision: Marissa , a 10th-grade physics student, is studying gravity and its role in planetary motion. She goes to the virtual science lab and navigates to the gravity room. In the gravity room, she discovers two other students, Randy and David, already working with the Alternate Reality Kit, which allows students to alter various physical parameters (such as the universal gravitational constant) and then observe effects in a simulation world. The three students, each of whom is from a different school in the county, discuss possible experiments by typing messages from their respective personal computers. Together they build and analyze several solar systems, eventually focusing on the question of how comets can disrupt otherwise stable systems. They capture data from their experiments and display it with several visualization tools, then write a brief report of their experiments, sending it for comments to Don, another student in Marissa’s class, and Mr. Arkins, Randy’s physics teacher.

Scenario Elements Setting Actors (people, users) Task goals (what I want to achieve) Plans (how I will accomplish it) Actions (do it) Events (system response) Evaluation (is that what I wanted?)

Advantages of Scenarios

Information scenarios ANALYZE analysis of stakeholders, field studies claims about current practice Problem scenarios DESIGN Activity scenarios metaphors, information technology, HCI theory, guidelines iterative analysis of usability claims and re-design Information scenarios Interaction scenarios PROTOTYPE & EVALUATE summative evaluation formative evaluation Usability specifications

Iterative Fuzzy -> clear

Iterative Fuzzy -> clear

Iterative Sometimes “design is radically transformational”

Summary Measurable Metrics! Tradeoffs Claims Scenarios, elements Scenario-based UE process Iterative

The Changing Face of Computer Use Professional programmers, “software psychology” 1960’s Business professionals, mainframes, command-line 1970’s Large, diverse user groups, “the computer for the rest of us” 1980’s World Wide Web and more, information access & overload 1990’s Ubiquitous computing, diversity in task, device, … 2000+

Some History of HCI Vannevar Bush, 1945 “As We May Think” Vision of post-war activities, Memex “…when one of these items is in view, the other can be instantly recalled merely by tapping a button”

Some History of HCI Douglas Engelbart, 1962 “Augmenting Human Intellect: A Conceptual Framework” In 1968, workstation with a mouse, links across documents, chorded keyboard

Some History of HCI XEROX (PARC) Alto and Star Apple LISA and Mac Windows Menus Scrollbars Pointing Consistency OOP Networked Apple LISA and Mac Inexpensive High-quality graphics 3rd party applications

Future of HCI Large displays Small displays Peripheral displays Alternative I/O Ubiquitous computing Virtual environments Augmented Reality Speech recognition Multimedia Media space Artificial intelligence Software agents Games ...

HCI at VT Doug Bowman Scott McCrickard Chris North Manuel Perez Francis Quek Deborah Tatar Steve Harrison Grad students & HCI Center researchers

Presentations (Hall of Fame/Shame) In Project teams 5% of grade 5 minutes, 3-4 slides Bring on CD, floppy Practice Pick UI of your choice (software or real-world) UI critique Scenarios/tasks Good Bad Redesign ideas? Vote: UI Hall of Fame/Shame

Fast Food Drive-Thru Menus Scenarios: College students Hungry Get food, get out. FAST! Often: sandwich, fries, drink Typically: Not sure what I want Sometimes: Know what I want Passengers want food too Budget is important

The Good All in one view Organized by categories Tabular format: left aligned, prices aligned Combo meals (high frequency) Budget menu (Wendy’s) Get price before proceeding Some: feedback on order

The Bad See menu too late Passengers cant see menu Passengers must order thru driver Winter: brrrrr… Small Redesign ideas: More menus back in line Menu on both sides of car Microphone on both sides Radical: cell phone, in-car UI

The Ugly I can’t understand a word they say They cant hear me over my ’87 VW