Task Analysis

Agenda

Questions? Task Analysis Practice Project part 1 reminder

Persona assignment

Rachel is 24, newly married to the love of her life Morgan, 26. Rachel teaches 2nd grade at the near by Elementary School while Morgan works at the local water treatment plant. They both work 5 days a week, Rachel from the hours of 7:00AM - 4:00PM and Morgan from 6:00AM - 2:30PM. Since both of their work schedules vary significantly, they own two cars, driving to and from work separately. Planning meals can be difficult for the couple. It is hard for Morgan to call Rachel and see what is for dinner, for she cannot answer her cell phone during teaching and vice a versa for Morgan while he is at the plant. Morgan likes to have dinner ready for Rachel when she walks into the door from work, but Rachel is the one who does the grocery shopping and who tends to know what is on hand to cook. Morgan occasionally stops by the local supermarket to pick up what he has a taste for at dinner on his way home from work, but then is told at home by Rachel that there is food already at the house and there is no need to spend more money at the supermarket. Rachel uses the new technology from Food Networking that shows what is available for her to cook and then displays it to Morgan in the morning, showing him what could be made for dinner that evening. Morgan can now prepare meals for Rachel, avoiding the frequent stops to the supermarket on his way home from work and using what is already at the house, eliminating waste.

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 annotationsGoal

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

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

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!

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– 3 levels deep should be sufficient

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?

Project Part 1 reminder

Due Feb. 12 (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