Formal Methods for Interactive Systems Part 3 Task Analysis - - PowerPoint PPT Presentation

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Formal Methods for Interactive Systems Part 3 Task Analysis - - PowerPoint PPT Presentation

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Formal Methods for Interactive Systems Part 3 Task Analysis Antonio Cerone United Nations University International Institute for Software Technology Macau SAR China email: antonio@iist.unu.edu web: www.iist.unu.edu A. Cerone, UNU-IIST

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SLIDE 1

Formal Methods for Interactive Systems

Part 3 — Task Analysis Antonio Cerone United Nations University International Institute for Software Technology Macau SAR China email: antonio@iist.unu.edu web: www.iist.unu.edu

  • A. Cerone, UNU-IIST – p.1/38
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SLIDE 2

Tasks and Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

Task: the activity that has to be performed to achieve a goal

  • A. Cerone, UNU-IIST – p.2/38
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SLIDE 3

Tasks and Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

Task: the activity that has to be performed to achieve a goal Task Analysis: the process of analysing the way people perform tasks:

  • what people do
  • what things they work with
  • what they must know
  • A. Cerone, UNU-IIST – p.2/38
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SLIDE 4

Method for Task analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

General Method

  • observe the user’s behaviour
  • collect unstructured lists of words and actions
  • organise using notation or diagrams
  • A. Cerone, UNU-IIST – p.3/38
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SLIDE 5

Method for Task analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

General Method

  • observe the user’s behaviour
  • collect unstructured lists of words and actions
  • organise using notation or diagrams

Focus on the user’s objective obsevable behaviour rather than on the user’s internal mental model

  • A. Cerone, UNU-IIST – p.3/38
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SLIDE 6

Method for Task analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

General Method

  • observe the user’s behaviour
  • collect unstructured lists of words and actions
  • organise using notation or diagrams

Focus on the user’s objective obsevable behaviour rather than on the user’s internal mental model However, it might involve building a conceptual model

  • A. Cerone, UNU-IIST – p.3/38
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SLIDE 7

Purpose of Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

  • production of training material and

documentation

  • A. Cerone, UNU-IIST – p.4/38
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SLIDE 8

Purpose of Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

  • production of training material and

documentation

  • contribute to the design of a new system
  • building a conceptual model
  • generation of user interfaces
  • A. Cerone, UNU-IIST – p.4/38
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SLIDE 9

Approaches to Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

Three different approaches:

  • A. Cerone, UNU-IIST – p.5/38
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SLIDE 10

Approaches to Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

Three different approaches:

  • task decomposition
  • knowledge-based techniques
  • entity-relationship-based analysis
  • A. Cerone, UNU-IIST – p.5/38
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SLIDE 11

Task Decomposition

What | Task Decomposition | Task Knowledge | Task ER | Use

  • describe the actions people do
  • structure them within task-subtask hierarchy
  • describe order of subtasks
  • A. Cerone, UNU-IIST – p.6/38
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SLIDE 12

Task Decomposition

What | Task Decomposition | Task Knowledge | Task ER | Use

  • describe the actions people do
  • structure them within task-subtask hierarchy
  • describe order of subtasks

Hierarchical Task Analysis (HTA)

  • text and diagrams to show hierarchy
  • plans to describe order
  • A. Cerone, UNU-IIST – p.6/38
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SLIDE 13

HTA: Textual Notation

What | Task Decomposition | Task Knowledge | Task ER | Use

Hierarchy description:

  • 0. make a cup of tea
  • 1. boil water
  • 2. empty pot
  • 3. put tea leaves in pot
  • 4. pour in boiling water
  • 5. wait 5 minutes
  • 6. pour tea
  • A. Cerone, UNU-IIST – p.7/38
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SLIDE 14

HTA: Textual Notation

What | Task Decomposition | Task Knowledge | Task ER | Use

Hierarchy description:

  • 0. make a cup of tea
  • 1. boil water
  • 2. empty pot
  • 3. put tea leaves in pot
  • 4. pour in boiling water
  • 5. wait 5 minutes
  • 6. pour tea

Plans Plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 after 5 minutes do 6

  • A. Cerone, UNU-IIST – p.7/38
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SLIDE 15

Generating the Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use

  • get list of tasks
  • group tasks into higher level tasks
  • decompose lower level tasks further
  • A. Cerone, UNU-IIST – p.8/38
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SLIDE 16

Generating the Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use

  • get list of tasks
  • group tasks into higher level tasks
  • decompose lower level tasks further

How to know when to stop?

  • A. Cerone, UNU-IIST – p.8/38
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SLIDE 17

Generating the Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use

  • get list of tasks
  • group tasks into higher level tasks
  • decompose lower level tasks further

How to know when to stop? Stopping rules:

  • Simplicity: Is the task simple enough?
  • Purpose: Is the task relevant?
  • Motor Action: lowest sensible level
  • A. Cerone, UNU-IIST – p.8/38
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SLIDE 18

HTA: Diagrammatic Notation

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. put tea leaves in pot 4. pour in boiling water 5. wait 5 minutes 6. pour tea plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 after 5 minutes do 6

  • A. Cerone, UNU-IIST – p.9/38
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SLIDE 19

HTA: Decomposition

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

2. empty pot 3. put tea leaves in pot 4. pour in boiling water 5. wait 5 minutes 6. pour tea plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 after 5 minutes do 6 1. boil water

  • A. Cerone, UNU-IIST – p.10/38
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SLIDE 20

HTA: Decomposition

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

2. empty pot 3. put tea leaves in pot 4. pour in boiling water 5. wait 5 minutes 6. pour tea plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 after 5 minutes do 6 1. boil water 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

  • A. Cerone, UNU-IIST – p.10/38
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SLIDE 21

HTA: Domain Expert

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. put tea leaves in pot 4. pour in boiling water 5. wait 5 minutes 6. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 after 5 minutes do 6 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Looking for errors Describe the step in the task hierarchy to a domain expert

  • A. Cerone, UNU-IIST – p.11/38
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SLIDE 22

HTA: Domain Expert

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. put tea leaves in pot 4. pour in boiling water 5. wait 5 minutes 6. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 after 5 minutes do 6 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Looking for errors Describe the step in the task hierarchy to a domain expert We forgot to warm the pot

  • A. Cerone, UNU-IIST – p.11/38
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SLIDE 23

HTA: Domain Expert

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. put tea leaves in pot 4. pour in boiling water 5. wait 5 minutes 6. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 after 5 minutes do 6 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Looking for errors Describe the step in the task hierarchy to a domain expert We forgot to warm the pot

✻

  • A. Cerone, UNU-IIST – p.11/38
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SLIDE 24

HTA: Omissions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

  • A. Cerone, UNU-IIST – p.12/38
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SLIDE 25

HTA: Omissions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Omissions?

  • A. Cerone, UNU-IIST – p.12/38
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SLIDE 26

HTA: Omissions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Omissions?

✬ ✫ ✩ ✪

  • A. Cerone, UNU-IIST – p.12/38
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SLIDE 27

HTA: Omissions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Omissions?

✬ ✫ ✩ ✪

Where do we turn the gas on?

  • A. Cerone, UNU-IIST – p.12/38
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SLIDE 28

HTA: Omissions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Omissions?

✬ ✫ ✩ ✪

Where do we turn the gas on? Maybe implicit in

❄ ✬ ✫ ✩ ✪

  • A. Cerone, UNU-IIST – p.12/38
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SLIDE 29

HTA: Omissions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. wait for kettle to boil 1.4. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Omissions?

✬ ✫ ✩ ✪

Where do we turn the gas on? We make it explicit here

❄

  • A. Cerone, UNU-IIST – p.12/38
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SLIDE 30

HTA: Umbalanced Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

  • A. Cerone, UNU-IIST – p.13/38
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SLIDE 31

HTA: Umbalanced Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Why is the hierarchy unbalanced?

  • A. Cerone, UNU-IIST – p.13/38
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SLIDE 32

HTA: Umbalanced Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Why is the hierarchy unbalanced? Maybe too many details at the high level

  • A. Cerone, UNU-IIST – p.13/38
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SLIDE 33

HTA: Umbalanced Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Why is the hierarchy unbalanced? Maybe too many details at the high level

✬ ✫ ✩ ✪

  • A. Cerone, UNU-IIST – p.13/38
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SLIDE 34

HTA: Umbalanced Hierarchy

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. warm pot 4. put tea leaves in pot 5. pour in boiling water 6. wait 5 minutes 7. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 – 5 – 6 after 5 minutes do 7 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5

Why is the hierarchy unbalanced? Maybe too many details at the high level

✬ ✫ ✩ ✪

We add new make pot node which encompass tasks 3, 4, 5. Why not 2 and 6?

  • A. Cerone, UNU-IIST – p.13/38
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SLIDE 35

HTA: Further Decompositions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3

  • A. Cerone, UNU-IIST – p.14/38
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SLIDE 36

HTA: Further Decompositions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3

✬ ✫ ✩ ✪

basic basic

  • A. Cerone, UNU-IIST – p.14/38
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SLIDE 37

HTA: Further Decompositions

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make a cup

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3

✬ ✫ ✩ ✪

5.1. put milk in cup 5.2. fill cup with tea 5.3. add sugar plan 5. do 5.1 – 5.2 if desired do 5.3

  • A. Cerone, UNU-IIST – p.14/38
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SLIDE 38

HTA: Iteration

What | Task Decomposition | Task Knowledge | Task ER | Use 0.

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas 5.1. put milk in cup 5.2. fill cup with tea 5.3. 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 add sugar make a cup

✬ ✫ ✩ ✪

plan 5. do 5.1 – 5.2 if desired do 5.3

  • A. Cerone, UNU-IIST – p.15/38
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SLIDE 39

HTA: Iteration

What | Task Decomposition | Task Knowledge | Task ER | Use 0.

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas 5.1. put milk in cup 5.2. fill cup with tea 5.3. 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 make cups

✗ ✖ ✔ ✕

add sugar plan 5. do 5.1 – 5.2 if desired do 5.3

  • A. Cerone, UNU-IIST – p.15/38
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SLIDE 40

HTA: Iteration

What | Task Decomposition | Task Knowledge | Task ER | Use 0.

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas 5.1. put milk in cup 5.2. fill cup with tea 5.3. 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 make cups plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 add sugar

✬ ✫ ✩ ✪

  • A. Cerone, UNU-IIST – p.15/38
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SLIDE 41

HTA: Final Decomposition

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make cups

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 5.1. put milk in cup 5.2. fill cup with tea 5.3. do sugar 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water 5.3.1. ask guest about sugar 5.3.2. add sugar to taste 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 – 1.4 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 plan 5.3. do 5.3.1 – if wanted 5.3.2

  • A. Cerone, UNU-IIST – p.16/38
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SLIDE 42

HTA: Fixed Sequence

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make cups

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 5.1. put milk in cup 5.2. fill cup with tea 5.3. do sugar 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water 5.3.1. ask guest about sugar 5.3.2. add sugar to taste 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 – 1.4 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 plan 5.3. do 5.3.1 – if wanted 5.3.2

  • A. Cerone, UNU-IIST – p.17/38
slide-43
SLIDE 43

HTA: Optional Tasks

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make cups

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 5.1. put milk in cup 5.2. fill cup with tea 5.3. do sugar 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water 5.3.1. ask guest about sugar 5.3.2. add sugar to taste 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 – 1.4 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 plan 5.3. do 5.3.1 – if wanted 5.3.2

  • A. Cerone, UNU-IIST – p.18/38
slide-44
SLIDE 44

HTA: Waiting for Events

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make cups

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 5.1. put milk in cup 5.2. fill cup with tea 5.3. do sugar 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water 5.3.1. ask guest about sugar 5.3.2. add sugar to taste 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 – 1.4 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 plan 5.3. do 5.3.1 – if wanted 5.3.2

  • A. Cerone, UNU-IIST – p.19/38
slide-45
SLIDE 45

HTA: Cycles

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make cups

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 5.1. put milk in cup 5.2. fill cup with tea 5.3. do sugar 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water 5.3.1. ask guest about sugar 5.3.2. add sugar to taste 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 – 1.4 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 plan 5.3. do 5.3.1 – if wanted 5.3.2

  • A. Cerone, UNU-IIST – p.20/38
slide-46
SLIDE 46

HTA: Time-sharing

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make cups

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 5.1. put milk in cup 5.2. fill cup with tea 5.3. do sugar 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water 5.3.1. ask guest about sugar 5.3.2. add sugar to taste 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 – 1.4 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 plan 5.3. do 5.3.1 – if wanted 5.3.2

  • A. Cerone, UNU-IIST – p.21/38
slide-47
SLIDE 47

HTA: Mixtures

What | Task Decomposition | Task Knowledge | Task ER | Use 0. make cups

  • f tea

1. boil water 2. empty pot 3. make pot 4. wait 5 minutes 5. pour tea 5.1. put milk in cup 5.2. fill cup with tea 5.3. do sugar 3.1. warm pot 3.2. put tea leaves in pot 3.3. pour in boiling water 5.3.1. ask guest about sugar 5.3.2. add sugar to taste 1.1. fill kettle 1.2. put kettle

  • n stove

1.3. turn on and light gas 1.4. wait for kettle to boil 1.5. turn off gas plan 0. do 1 at the same time, if pot is full do 2 then do 3 – 4 after 5 minutes do 5 plan 1. do 1.1 – 1.2 – 1.3 – 1.4 when kettle boils do 1.5 plan 3. do 3.1 – 3.2 – 3.3 plan 5. 5.1

✲ 5.2 ✲ empty

cups? YES

✒ ✑ ✻ ✻

NO for each guest do 5.3 plan 5.3. do 5.3.1 – if wanted 5.3.2

  • A. Cerone, UNU-IIST – p.22/38
slide-48
SLIDE 48

Decomposition Heuristics

What | Task Decomposition | Task Knowledge | Task ER | Use

  • paired actions

e.g., turn on and turn on gas

  • restructure/balance e.g., generate make pot

and decompose pour tea

  • generalise

e.g., from make a cup of tea to make cups of tea

  • A. Cerone, UNU-IIST – p.23/38
slide-49
SLIDE 49

Knowledge-based Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

  • list objects used in tasks
  • list actions performed
  • build taxomomies of them
  • A. Cerone, UNU-IIST – p.24/38
slide-50
SLIDE 50

Knowledge-based Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

  • list objects used in tasks
  • list actions performed
  • build taxomomies of them

Aim

  • to understand knowledge needed to perform a

task

  • =

⇒ help in production of teaching material

  • =

⇒ assess the amount of common knowledge between different tasks

  • A. Cerone, UNU-IIST – p.24/38
slide-51
SLIDE 51

Knowledge-based Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

  • list objects used in tasks
  • list actions performed
  • build taxomomies of them

Aim

  • to understand knowledge needed to perform a

task

  • =

⇒ help in production of teaching material

  • =

⇒ assess the amount of common knowledge between different tasks Technique: Task Analysis for Knowledge Descrip- tion — TAKD

  • A. Cerone, UNU-IIST – p.24/38
slide-52
SLIDE 52

Example: Kitchen Items

What | Task Decomposition | Task Knowledge | Task ER | Use

kitchen items preparation bowl, plate, chopping board cooking frying pan, casserole, saucepan dining plate, soup bowl, casserole, glass

  • A. Cerone, UNU-IIST – p.25/38
slide-53
SLIDE 53

TDH notation

What | Task Decomposition | Task Knowledge | Task ER | Use

TDH — Task Descriptive Hierarchy kitchen item OR {___ preparation {___ cooking { frying pan, casserole, saucepan {___ dining { bowl, plate, chopping board plate, soup bowl, casserole, glass

  • A. Cerone, UNU-IIST – p.26/38
slide-54
SLIDE 54

TDH notation

What | Task Decomposition | Task Knowledge | Task ER | Use

TDH — Task Descriptive Hierarchy kitchen item OR {___ preparation {___ cooking { frying pan, casserole, saucepan {___ dining Uniqueness Rule: A complete TDH can distinguish any two specific objects { bowl, plate, chopping board plate, soup bowl, casserole, glass

  • A. Cerone, UNU-IIST – p.26/38
slide-55
SLIDE 55

TDH notation

What | Task Decomposition | Task Knowledge | Task ER | Use

TDH — Task Descriptive Hierarchy kitchen item OR {___ preparation {___ cooking { frying pan, casserole, saucepan {___ dining Uniqueness Rule: A complete TDH can distinguish any two specific objects { bowl, plate, chopping board plate, soup bowl, casserole, glass

  • A. Cerone, UNU-IIST – p.26/38
slide-56
SLIDE 56

TDH: Branching Type

What | Task Decomposition | Task Knowledge | Task ER | Use

kitchen item AND /___ function OR / {___ preparation / {___ cooking / { frying pan, casserole, saucepan / {___ dining XOR / |___ for food / |___ for drink /___ shape XOR ... / { bowl, plate, chopping board / | plate, soup bowl, casserole / glass

  • A. Cerone, UNU-IIST – p.27/38
slide-57
SLIDE 57

TDH: Branching Type

What | Task Decomposition | Task Knowledge | Task ER | Use

kitchen item AND /___ function OR / {___ preparation / {___ cooking / { frying pan, casserole, saucepan / {___ dining XOR / |___ for food / |___ for drink /___ shape XOR ...

KRG — Knowledge Representation Grammar

/ { bowl, plate, chopping board

kitchen item/function{dining(for food)/shape(dished)}/

/ | plate, soup bowl, casserole / glass

  • A. Cerone, UNU-IIST – p.27/38
slide-58
SLIDE 58

TDH: Branching Type

What | Task Decomposition | Task Knowledge | Task ER | Use

kitchen item AND /___ function OR / {___ preparation / {___ cooking / { frying pan, casserole, saucepan / {___ dining XOR / |___ for food / |___ for drink /___ shape XOR ...

KRG — Knowledge Representation Grammar KRG — Knowledge Representation Grammar

/ { bowl, plate, chopping board

kitchen item/function{dining(for drink)/shape(dished)}/

/ | plate, soup bowl, casserole / glass

  • A. Cerone, UNU-IIST – p.27/38
slide-59
SLIDE 59

TDH: Branching Type

What | Task Decomposition | Task Knowledge | Task ER | Use

kitchen item AND /___ function OR / {___ preparation / {___ cooking / { frying pan, casserole, saucepan / {___ dining XOR / |___ for food / |___ for drink /___ shape XOR ...

KRG — Knowledge Representation Grammar KRG — Knowledge Representation Grammar

/ { bowl, plate, chopping board

kitchen item/function{preparation,dining(for food)/shape(flat)}/ KRG — Knowledge Representation Grammar

/ | plate, soup bowl, casserole / glass

  • A. Cerone, UNU-IIST – p.27/38
slide-60
SLIDE 60

Taxomomy of Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

kitchen job OR {___ preparation { beating, mixing {___ cooking { frying, boiling, baking {___ dining pouring, eating, drinking

  • A. Cerone, UNU-IIST – p.28/38
slide-61
SLIDE 61

ER-based techniques

What | Task Decomposition | Task Knowledge | Task ER | Use

Entity-Relationship Based Techniques

  • list objects used in tasks
  • list actions performed
  • define relationships between object and

actions

  • A. Cerone, UNU-IIST – p.29/38
slide-62
SLIDE 62

ER-based techniques

What | Task Decomposition | Task Knowledge | Task ER | Use

Entity-Relationship Based Techniques

  • list objects used in tasks
  • list actions performed
  • define relationships between object and

actions

  • similar to techniques used in database and

OO

  • but includes non-computer entities
  • emphasis on domain understanding rather

than implementation

  • A. Cerone, UNU-IIST – p.29/38
slide-63
SLIDE 63

Example: Vera’s Veggies

What | Task Decomposition | Task Knowledge | Task ER | Use

  • Vera’s Veggies a market gardening firm
  • owner/manager: Vera
  • employes: Sam and Tony
  • tools include a tractor Fergie
  • two fields and a glasshouse
  • new computer controlled irrigation system
  • A. Cerone, UNU-IIST – p.30/38
slide-64
SLIDE 64

Object Classification

What | Task Decomposition | Task Knowledge | Task ER | Use

  • concrete objects

simple things: spade, plough, glasshouse

  • A. Cerone, UNU-IIST – p.31/38
slide-65
SLIDE 65

Object Classification

What | Task Decomposition | Task Knowledge | Task ER | Use

  • concrete objects

simple things: spade, plough, glasshouse

  • actors

human: Vera, Sam, Tony, the customers

  • A. Cerone, UNU-IIST – p.31/38
slide-66
SLIDE 66

Object Classification

What | Task Decomposition | Task Knowledge | Task ER | Use

  • concrete objects

simple things: spade, plough, glasshouse

  • actors

human: Vera, Sam, Tony, the customers non-human: irrigation system

  • A. Cerone, UNU-IIST – p.31/38
slide-67
SLIDE 67

Object Classification

What | Task Decomposition | Task Knowledge | Task ER | Use

  • concrete objects

simple things: spade, plough, glasshouse

  • actors

human: Vera, Sam, Tony, the customers non-human: irrigation system

  • composite objects

sets: the team = Vera, Sam, Tony

  • A. Cerone, UNU-IIST – p.31/38
slide-68
SLIDE 68

Object Classification

What | Task Decomposition | Task Knowledge | Task ER | Use

  • concrete objects

simple things: spade, plough, glasshouse

  • actors

human: Vera, Sam, Tony, the customers non-human: irrigation system

  • composite objects

sets: the team = Vera, Sam, Tony tuples: tractor = < Fergie, plough>

  • A. Cerone, UNU-IIST – p.31/38
slide-69
SLIDE 69

Attributes

What | Task Decomposition | Task Knowledge | Task ER | Use

An irrigation pump may have:

  • status: on/off/faulty
  • capacity: 100 litres/minute
  • A. Cerone, UNU-IIST – p.32/38
slide-70
SLIDE 70

Attributes

What | Task Decomposition | Task Knowledge | Task ER | Use

An irrigation pump may have:

  • status: on/off/faulty
  • capacity: 100 litres/minute

However, emphasis on object participation in tasks:

  • keep only relevant attributes (e.g., status)
  • no need for completeness, but convenient to

be initially overinclusive and drop unnecessary attributes later

  • A. Cerone, UNU-IIST – p.32/38
slide-71
SLIDE 71

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient

  • A. Cerone, UNU-IIST – p.33/38
slide-72
SLIDE 72

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks

  • A. Cerone, UNU-IIST – p.33/38
slide-73
SLIDE 73

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks using Instrument

  • A. Cerone, UNU-IIST – p.33/38
slide-74
SLIDE 74

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks using Instrument Tony dug the field with the spade

  • A. Cerone, UNU-IIST – p.33/38
slide-75
SLIDE 75

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks using Instrument Tony dug the field with the spade Vera turns on the irrigation system

  • A. Cerone, UNU-IIST – p.33/38
slide-76
SLIDE 76

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks using Instrument Tony dug the field with the spade Vera turns on the irrigation system irrigation system is turned on (control) (automatically)

  • A. Cerone, UNU-IIST – p.33/38
slide-77
SLIDE 77

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks using Instrument Tony dug the field with the spade Vera turns on the irrigation system irrigation system is turned on (control) (automatically) Vera programmed the irrigation system ... (indirect agent)

  • A. Cerone, UNU-IIST – p.33/38
slide-78
SLIDE 78

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks using Instrument Tony dug the field with the spade Vera turns on the irrigation system irrigation system is turned on (control) (automatically) Vera programmed the irrigation system ... (indirect agent) Vera told Sam to ... (message)

  • A. Cerone, UNU-IIST – p.33/38
slide-79
SLIDE 79

Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Agent performs Action to change Patient Sam planted the leeks using Instrument Tony dug the field with the spade Vera turns on the irrigation system irrigation system is turned on (control) (automatically) Vera programmed the irrigation system ... (indirect agent) Vera told Sam to ... (message) Vera as worker ... Vera as manager ... (agents may act in several roles)

  • A. Cerone, UNU-IIST – p.33/38
slide-80
SLIDE 80

Object and Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Sam human actor Actions: S1: drive tractor S2: dig carrots

  • A. Cerone, UNU-IIST – p.34/38
slide-81
SLIDE 81

Object and Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Sam human actor Actions: S1: drive tractor S2: dig carrots Object Vera human actor | the proprietor Actions: as worker V1: plant marrow seed V2: programme irrigation controller Actions: as manager V3: tell sam to dig the carrots

  • A. Cerone, UNU-IIST – p.34/38
slide-82
SLIDE 82

Object and Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Sam human actor Actions: S1: drive tractor S2: dig carrots Object Vera human actor | the proprietor Actions: as worker V1: plant marrow seed V2: programme irrigation controller Actions: as manager V3: tell sam to dig the carrots Object the men composite Comprises: Sam, Tony

  • A. Cerone, UNU-IIST – p.34/38
slide-83
SLIDE 83

Object and Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Sam human actor Actions: S1: drive tractor S2: dig carrots Object Vera human actor | the proprietor Actions: as worker V1: plant marrow seed V2: programme irrigation controller Actions: as manager V3: tell sam to dig the carrots Object the men composite Comprises: Sam, Tony Object glasshouse simple Attribute: humidity: 0–100%

  • A. Cerone, UNU-IIST – p.34/38
slide-84
SLIDE 84

Object and Actions

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Sam human actor Actions: S1: drive tractor S2: dig carrots Object Vera human actor | the proprietor Actions: as worker V1: plant marrow seed V2: programme irrigation controller Actions: as manager V3: tell sam to dig the carrots Object the men composite Comprises: Sam, Tony Object glasshouse simple Attribute: humidity: 0–100% Object Irrigation Controller non-human Actions: IC1: turn on Pump 1 IC2: turn on Pump 2 IC3: turn on Pump 3

  • A. Cerone, UNU-IIST – p.34/38
slide-85
SLIDE 85

Events

What | Task Decomposition | Task Knowledge | Task ER | Use

  • performing of an action

Sam dug the carrots

  • A. Cerone, UNU-IIST – p.35/38
slide-86
SLIDE 86

Events

What | Task Decomposition | Task Knowledge | Task ER | Use

  • performing of an action

Sam dug the carrots

  • spontaneous events

the marrow seeds germinated

  • A. Cerone, UNU-IIST – p.35/38
slide-87
SLIDE 87

Events

What | Task Decomposition | Task Knowledge | Task ER | Use

  • performing of an action

Sam dug the carrots

  • spontaneous events

the marrow seeds germinated the humidity drops below 25%

  • A. Cerone, UNU-IIST – p.35/38
slide-88
SLIDE 88

Events

What | Task Decomposition | Task Knowledge | Task ER | Use

  • performing of an action

Sam dug the carrots

  • spontaneous events

the marrow seeds germinated the humidity drops below 25%

  • timed events

at midnight

  • A. Cerone, UNU-IIST – p.35/38
slide-89
SLIDE 89

Relationships

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Marrow simple Actions: M1: germinate M2: grow

  • A. Cerone, UNU-IIST – p.36/38
slide-90
SLIDE 90

Relationships

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Marrow simple Actions: M1: germinate M2: grow Events Ev1: humidity drops below 25% Ev2: midnight

  • A. Cerone, UNU-IIST – p.36/38
slide-91
SLIDE 91

Relationships

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Marrow simple Actions: M1: germinate M2: grow Events Ev1: humidity drops below 25% Ev2: midnight Relations object-object location ( Pump 1, glasshouse )

  • A. Cerone, UNU-IIST – p.36/38
slide-92
SLIDE 92

Relationships

What | Task Decomposition | Task Knowledge | Task ER | Use

Object Marrow simple Actions: M1: germinate M2: grow Events Ev1: humidity drops below 25% Ev2: midnight Relations object-object location ( Pump 1, glasshouse ) Relation action-object patient ( V3, Sam ) — Vera tells Sam to dig patient ( S2, the carrots ) — Sam digs the carrots ... instrument ( S2, spade ) — ... with the spade

  • A. Cerone, UNU-IIST – p.36/38
slide-93
SLIDE 93

Relations action-event

What | Task Decomposition | Task Knowledge | Task ER | Use

Relations action-event before ( V1, M1 ) — the marrow must be sown before it can germinate before ( M1, M2 ) — the marrow must germinate before it can grow V1: plant marrow seed M1: germinate M2: grow

  • A. Cerone, UNU-IIST – p.37/38
slide-94
SLIDE 94

Relations action-event

What | Task Decomposition | Task Knowledge | Task ER | Use

Relations action-event before ( V1, M1 ) — the marrow must be sown before it can germinate before ( M1, M2 ) — the marrow must germinate before it can grow triggers ( Ev2, IC1 ) — when it is midnight the control turns on Pump 1 Ev1: humidity drops below 25% IC1: turn on Pump 1

  • A. Cerone, UNU-IIST – p.37/38
slide-95
SLIDE 95

Relations action-event

What | Task Decomposition | Task Knowledge | Task ER | Use

Relations action-event before ( V1, M1 ) — the marrow must be sown before it can germinate before ( M1, M2 ) — the marrow must germinate before it can grow triggers ( Ev2, IC1 ) — when it is midnight the control turns on Pump 1 causes ( V2, IC1 ) — the controller turns on Pump1 because Vera programmed it V2: programme irrigation controller IC1: turn on Pump 1

  • A. Cerone, UNU-IIST – p.37/38
slide-96
SLIDE 96

Relations action-event

What | Task Decomposition | Task Knowledge | Task ER | Use

Relations action-event before ( V1, M1 ) — the marrow must be sown before it can germinate before ( M1, M2 ) — the marrow must germinate before it can grow triggers ( Ev2, IC1 ) — when it is midnight the control turns on Pump 1 causes ( V2, IC1 ) — the controller turns on Pump1 because Vera programmed it causes ( V3, S2 ) — Sam digs the carrots because Vera told him to do so V3: tell sam to dig the carrots S2: dig carrots

  • A. Cerone, UNU-IIST – p.37/38
slide-97
SLIDE 97

Relations action-event

What | Task Decomposition | Task Knowledge | Task ER | Use

Relations action-event before ( V1, M1 ) — the marrow must be sown before it can germinate before ( M1, M2 ) — the marrow must germinate before it can grow triggers ( Ev2, IC1 ) — when it is midnight the control turns on Pump 1 causes ( V2, IC1 ) — the controller turns on Pump1 because Vera programmed it causes ( V3, S2 ) — Sam digs the carrots because Vera told him to do so Ordering of events better described using HTA either to analyse order of subtasks and actions annotated with objects

  • r to represent the life-cycle of a specific object
  • A. Cerone, UNU-IIST – p.37/38
slide-98
SLIDE 98

Uses of Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

Purposes:

  • requirement capture and system design
  • lift focus from system to use
  • suggest candidates for automation
  • uncover user’s conceptual model
  • A. Cerone, UNU-IIST – p.38/38
slide-99
SLIDE 99

Uses of Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

Purposes:

  • requirement capture and system design
  • lift focus from system to use
  • suggest candidates for automation
  • uncover user’s conceptual model
  • interface design
  • taxonomies suggest menu layout
  • object/action lists suggest interface objects
  • task frequency guides default choices
  • task sequences guide dialogue design
  • A. Cerone, UNU-IIST – p.38/38
slide-100
SLIDE 100

Uses of Task Analysis

What | Task Decomposition | Task Knowledge | Task ER | Use

Purposes:

  • requirement capture and system design
  • lift focus from system to use
  • suggest candidates for automation
  • uncover user’s conceptual model
  • interface design
  • taxonomies suggest menu layout
  • object/action lists suggest interface objects
  • task frequency guides default choices
  • task sequences guide dialogue design
  • documentation and teaching
  • A. Cerone, UNU-IIST – p.38/38