Requirements and Task Analysis. Please attend!! Duke Hutchings: “Window interfaces for multiple monitor systems”: next Monday 2/6, 9:30-11, room 154 student.

Requirements and Task Analysis

Please attend!!

Duke Hutchings: “Window interfaces for multiple monitor systems”: next Monday 2/6, 9:30-11, room 154 student meeting: 2/6 2-2:45, room 338

Jeff Nichols: “Automatically Generating High-Quality User Interfaces for Appliances” next Thursday 2/9 2-3:30, room 356 student meeting: 2/10 1-1:45, room 338

George Chin: “Capturing, Representing, and Implementing Scientific Knowledge in Scientific Computing Environments”: 2/13 9:30-11, room 154 student meeting: 2/13 2-2:45, room 338

Celine Letulipe: “Symmetric Interaction Techniques”: 2/20 2-3:30, room 356 student meeting: 2/21 2:30-3:15, room 441

Project Part 1 reminder

Due Feb. 16 (2 weeks!) by class time READ description and template Focus on the problem, not the solution Start gathering your data now! Ask for help and feedback Good communication skills are key

And please spell and grammar check

Functional vs. NonFunctional

Historically requirements

Features, functions that the system should do

Properties of the overall system

“-ilities” (quality, evolveability, flexibility, etc.)

Environment User requirements Usability

requirements

Not just “requirements”

Overall goals, success criteria User characteristics Task analysis Environment – physical, social,

technical Constraints Usability goals, criteria

User Characteristics: Recall

Attitude, morale, willingness to change, motivation, reading level, typing skill, education, frequency of use, training, color-blindness, handedness, gender,…

Novice, intermediate, expert System experience, task experience,

computer literacy Cultural factors

Uses of icons, colors, words, metaphors

Task Analysis

• Process of analyzing and documenting how people perform their jobs or activities

• Task-subtask decomposition

• Focus on:• Activities• Artifacts• Relations

• More in a moment…

Physical Environment

Amount of space to work Lighting levels / directions Noise level Temperature, humidity, dust… Standing / sitting Power availability Dangers

Implications?

Technical Environment

Computers/platforms for application Technology to interact with Networking Mobility

Implications?

Social Environment

How do users interact? Roles? How do users interact with others? Social implications of problem or

solution?InterruptionPrivacy

Implications?

Stakeholders

Primary – targeted end users Secondary – receive output or provide

input to system Tertiary – others directly receiving

benefits from system success or failure

Facilitating – design, development, maintenance

Stakeholder analysis

Cell phone

Bus stop kiosk

Nuclear power plant control system

Typical Real-World Constraints Elapsed time to market Cost/effort to design and implement Size/footprint/weight/power/price Computer power/memory (related to cost

and power Consistency with overall product line Backward compatibility Differentiation from competitive products

Usability Requirements

Usability goals: such as learnability, consistency, robustness, etc.

Ways to measure and judge success Time to complete key tasks - min, max Time to become proficient - do given set of

tasks in given time Subjective satisfaction

Example

What factors (environmental, user, usability) would affect the following systems?

• Self-service filling and payment system for a gas station

• On-board ship data analysis system for geologists searching for oil

• Fashion website for buying clothes

Example: bus stop kiosk

User characteristics Context: Environment, types of users Constraints: device, market, etc. Functional requirements Non-functional requirements

How?

Gather data Interviews, observation,

surveys/questionnaires, documentation, immersion

Organize data Notes, cards, brainstorming, computer tools

Represent data Lists, outlines, matrices Narratives Hierarchies, Networks, Flow charts

Formative vs. Summative evaluation

Summative assess an existing

system judge if it meets some

criteria Formative

assess a system being designed

gather input to inform design

Summative or formative? Depends on

• maturity of system• how evaluation results

will be used

Same technique can be used for either

(Not All) Requirements Gathering Methods

Observation Thing out Loud & Cooperative EvaluationInterviewsQuestionnairesFocus groupsStudy DocumentationLook at competitive productsEthnographyContextual Inquiry

Study Documentation

Quick and easy if it exists Often describe how things should be

done rather than how they are doneTry to understand why not done “by

the book”

Alternative: interview domain expert

Look at Competitive Products

Looking for both good and bad ideasFunctionalityUI style

Possibly do user task performance metrics to establish bounds on your system

Ethnography

Deeply contextual study Immerse oneself in situation you want to

learn about (has anthropological and sociological roots) Observing people in their cultural context

Behavior is meaningful only in context For UI designers: understand current

methods, activities, environment, problems to aid design

Ethnography

Things of interest to evaluator Structure and language used in work Individual and group actions Culture affecting work Explicit and implicit aspects of work

Example: Office work environment Business practices, rooms, artifacts, work

standards, relationships between workers, managers, …

Drawbacks of Ethnographic Methods Time required

Can take weeks or months for large systems Scale

Most use small numbers of participants just to keep somewhat manageable

Type of results Highly qualitative, may be difficult to

present/use Acquired skill – “learn by doing”

Identifying and extracting “interesting” things is challenging

Contextual Inquiry

Practical ethnographic-inspired method for requirements

Master-apprentice relationshipWatch and talk to customer as they do

their work See: Beyer and Holtzblatt. Contextual

Design. Morgan Kaufmann Publishers

How compares to other methods?

Which Methods to Use?

• Self-service filling and payment system for a gas station

• On-board ship data analysis system for geologists searching for oil

• Fashion website for buying clothes at large department store

Making Sense

Organize/categorize information“coding scheme”

Card Sorting Affinity Diagrams Task analysis

Affinity Diagram - “Sorted Cards”

From Interaction Design, Preece Rogers and Sharp

Task Analysis

Focus on observable behaviors What are the practices, methods, steps, objects, …,

used?

Tasks & Subtasks Physical Cognitive Communication

Conditions under which these tasks are done Results/outcomes of tasks Requirements to perform task

Information, artifacts Communication with others Equipment

Also see: Hackos and Redish, User and Task Analysis for Interface Design. Wiley Publishing.

Describing activities

Scenarios Use Cases Task - subtask decomposition

Includes sequencing information Workflow diagrams Flow charts ER or object models

Scenario

Describe tasks and context in sentences Natural way of describing general idea

Good for demonstrating specific problems, reasons behind actions, atypical activities

Bad for representing branching, parallel activities, various possibilities of one activity

Scenario: Example 1

Its Friday afternoon and John just got paid. He wants to deposit his check immediately so he can pay his rent. He stops at one branch of his bank on the way home from work. He waits in his car while another person finishes using the ATM in front of the bank since it is drizzling outside. He walks up to the ATM to deposit his check. Only, as he is about to put the check into the envelope at the ATM, he realizes that he has not signed the back of it, and he has no pen and can not find one on or near the ATM machine. He cancels the transaction on the ATM, and enters the bank, which luckily is still open for 5 more minutes. He goes to the counter, finds a pen, and signs his check. He also fills out a deposit slip. He then waits to see a teller in person to deposit his check, and get money for the weekend.

Scenario: Example 2

Annie walks up to the ATM to deposit her weekly pay check. She puts her ATM card into the slot in the machine. She then enters her PIN number quickly, trying to block the person waiting behind her from viewing the keypad, and knows that she does not have to press “Enter” at this particular machine. She then chooses “Deposit” and “Check.” She enters the amount of the check using the keypad, then takes an envelope from the ATM machine, puts her check inside, seals the envelope and writes the amount of the check on the outside. She feeds the envelope into the slot into the ATM machine. She then selects “No other transactions” to finish, and waits to receive her receipt and ATM card.

Example

Register for classes

What kinds of activities could we write a scenario about?

Let’s write one together

Use Case

Description of a user’s goal in using a system

Focuses on user-system interaction One path through a use case is

sometimes called a scenarioOften presented as a series of steps

Diagram of actors and use cases

Use Case Diagram

Administrator Departmentalmember

Arrange ameeting

Update calendarentry

Retrievecontact details

Use Case example

Arrange Meeting1. The user chooses the option to arrange a meeting.2. The system prompts user for the names of attendees.3. The user types in a list of names.4. The system checks that the list is valid.5. The system prompts the user for meeting constraints.6. The user types in meeting constraints.7. The system searches the calendars for a date that satisfies

the constraints. 8. The system displays a list of potential dates.9. The user chooses one of the dates.10. The system writes the meeting into the calendar.11. The system emails all the meeting participants informing

them of them appointment

Hierarchical Task Analysis (HTA)

Graphical notation & decomposition of tasks Goals – what the user wants to achieve Tasks – do these to achieve the goals

Not necessarily computer related Sequential dependencies Multiple occurrences of tasks Subtasks – lower-level tasks

Tasks organized into plans Clusters of subtasks with a preferred order and

prerequisite conditions

From Interaction Design, Preece Rogers and Sharp

Task Model - Borrow Book

Sequences added as annotations

Can also show hierarchy as indented text

Goal

Tasks tocomplete goal

Subtasks tocarry outone task

HTA: Types of Plans

Fixed sequence Optional tasks Waiting events Cycles Time-sharing Discretionary

HTA

Example

Goal: register for classes

Flow Charts

Flow Chart of Task StepsComplete, can become complex

• Sequential flow, branching, parallel tasks.

Includes actions, decisions, logic, by all elements of the system

Mature, well-known, good tools for doing it

Flow Chart Example

Start

Continue? Document

Input

Display

ManualOperation

End

Y

N

Workflow

Documents going from one person/organization to another

Multiple participants in an activity

Create TravelRequest

(Traveler)

Approval(Dean)

Notification ofApproval

(Dean)

Ensure FundsAvailable

(Accounting)

Notification ofApproval

(Dean)

No Funds

Make Trip (Traveler)

CompleteExpense Report

(Traveler)

Approval(Accounting) Etc

Workflow Example - Document Flow

From Interaction Design, Preece Rogers and Sharp

Entity Relationship Diagrams

Object Oriented Models Objects/people with links to related objects

• Stress relationship between objects and actions

Links described functionally and in terms of strength

About relations, not procedures Complements HTA & flow charts

Object Model: ATM

Objects Account, ATM machine, ATM card, customer

Relations Customer has one or more accounts ATM machine accesses account

Actions on objects Account: deposit($), withdraw($), balance ATM machine: authenticate, dispense($),

print receipt Etc

Your turn

Create a scenario describing a CURRENT bus stop activity that would help describe requirements information for a bus stop kiosk

Create an HTA of that same activity Create ER diagram of entities

involved in that activity Is Workflow or Flow chart applicable?

Beyond Requirements

Task analysis throughout life cycle:Describe and document design ideasHelp design menu, dialog structureHelp create documentation and help

Task descriptions can be given at any necessary abstraction level

Summary

Determine what data you need Gather it using various appropriate

methods and techniques Represent the tasks and subtasks,

plus other related information Use this data as basis for design

Note: Be efficient!

Exercise: Movie Ticket Kiosk

What data gathering techniques would you use? Who would you interact with?

Who are the stakeholders? What are typical user characteristics? What is physical/social/technical environment? What is a typical scenario of use? What is an atypical or problem scenario? What would you represent using HTA? What could you represent using ER diagram? What could you represent using flowchart?