Task Analysis

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Task Analysis

• Analyzing and representing the activities of your
  users

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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

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Describing requirements activities

• Narratives
• Personas
• Scenarios
• Task Analysis other task descriptions
• Use Cases
• Workflow
• ER diagrams

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Scenario Example

• Register for classes
• What kinds of activities could we write a
  scenario about?
• Lets write one together

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Use Case

• Description of a users 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

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Use Case Diagram
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Use Case example

• Arrange Meeting
• 1. 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

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Task Analysis

• Process of analyzing and documenting how people
  perform their jobs or activities
• Task-subtask decomposition

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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

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Task Model as an Outline - Example

• Using a lawnmower to cut grass
• Step 1. Examine lawn
• Make sure grass is dry
• Look for objects laying in the grass
• Step 2. Inspect lawnmower
• Check components for tightness
• Check that grass bag handle is securely fastened
  to the grass bag support
• Make sure grass bag connector is securely
  fastened to bag adaptor
• Make sure that deck cover is in place
• Check for any loose parts (such as oil caps)
• Check to make sure blade is attached securely
• Check engine oil level
• Remove oil fill cap and dipstick
• Wipe dipstick
• Replace dipstick completely in lawnmower
• Remove dipstick
• Check that oil is past the level line on dipstick

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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

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Task Model - Borrow Book

• Sequences added as annotations

Goal
Tasks to complete goal
Subtasks to carry out one task
From Interaction Design, Preece Rogers and Sharp
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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 catalogue
• 2.2 access the search screen
• 2.3 enter search criteria
• 2.4 identify required book
• 2.5 note location
• 3. go to correct shelf and retrieve book
• 4. take book to checkout counter

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HTA Types of Plans

• Fixed sequence
• Optional tasks
• Waiting events
• Cycles
• Time-sharing
• Discretionary

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Example

• Register for classes

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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

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Flow Chart Example
Start
Continue?
Document
Manual Operation
Y
Input
N
Display
End
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Workflow Example - Document Flow
Create Travel Request (Traveler)
Approval (Dean)
Notification of Approval (Dean)
Ensure Funds Available (Accounting)
No Funds
Notification of Approval (Dean)
Make Trip (Traveler)
Complete Expense Report (Traveler)
Approval (Accounting)
Etc
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From Interaction Design, Preece Rogers and Sharp
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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

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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

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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

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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?

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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!

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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?

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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

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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?