Task Analysis

Analyzing and representing the activities of your users

Project Part 1 reminder

Due Sept. 20 (2 weeks!) 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

Describing requirements activities

Narratives Personas Scenarios Task Analysis & other task

descriptions Use Cases Workflow ER diagrams

Scenario 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 scenario Often 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

Task Analysis

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

• Task-subtask decomposition

Task Decomposition

Break tasks down into subtasks Continue for as many levels as needed

…how many are needed? Not just for computer tasks, but any sort

of activity Easily supports sequential tasks Can support parallel tasks & branching Difficult to represent exceptions, errors

Task Model as an Outline - Example

Using a lawnmower to cut grassStep 1. Examine lawn

Make sure grass is dryLook for objects laying in the grass

Step 2. Inspect lawnmowerCheck components for tightness

Check that grass bag handle is securely fastened to the grass bag supportMake sure grass bag connector is securely fastened to bag adaptorMake sure that deck cover is in placeCheck for any loose parts (such as oil caps)Check to make sure blade is attached securely

Check engine oil levelRemove oil fill cap and dipstickWipe dipstickReplace dipstick completely in lawnmowerRemove dipstickCheck that oil is past the level line on dipstick…

Hierarchical Task Analysis (HTA)

Graphical notation & decomposition of tasks

Goals – what the user wants to achieve

Tasks – do these to achieve the goals 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

Goal

Tasks tocomplete goal

Subtasks tocarry outone task

Another representation

0. In order to borrow a book from the library 1. go to the library 2. find the required book

2.1 access library catalogue2.2 access the search screen2.3 enter search criteria2.4 identify required book 2.5 note location

3. go to correct shelf and retrieve book4. take book to checkout counter

HTA: Types of Plans

Fixed sequence Optional tasks Waiting events Cycles Time-sharing Discretionary

Example

Register for classes

Other task representations

Flow charts Ordering of task steps, can be complex Includes decisions logic and information Many tools to support

Workflow Flow of documents through people and

activities Entity Relationship Diagrams

Show objects and their relationships About relations, not procedures

Flow Chart Example

Start

Continue? Document

Input

Display

ManualOperation

End

Y

N

Create TravelRequest

(Traveler)

Approval(Dean)

Notification ofApproval

(Dean)

Ensure FundsAvailable

(Accounting)

Notification ofApproval

(Dean)

No Funds

Make Trip (Traveler)

Complete ExpenseReport

(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 describe 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

Beyond Requirements

Task analysis throughout life cycle: Describe and document design ideas Help design menu, dialog structure Help create documentation and help

Task descriptions can be given at any necessary abstraction level

Your turn

Create a scenario describing a CURRENT bus activity that would help describe requirements information for a bus locator service

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

involved in that activity Is Workflow or Flow chart applicable?

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!

Assignment: Persona

Think about all the characteristics of a user that may be important to your problem

Be specific but representative You should create multiple personas

for different types of users So what should distinguish each one?

Next assignment: Scenario

Similar to persona, but focus is on a task

Next next assignment: task analysis Do an HTA for a task/activity for your

project Activity is how it currently exists, NOT

what it would be like with you new system

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?