Task Analysis Lecture # 8 Gabriel Spitz 1. Key Points Task Analysis is a critical element of UI Design It describes what is a user doing or will

Task Analysis Lecture # 8

Gabriel SpitzGabriel Spitz

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Key Points

Task Analysis is a critical element of UI Design It describes what is a user doing or will s/he need to do

to achieve a specific goal It describes both the Steps to be performed and their

sequence It does it within the bigger context which is the Task

and Activity

Interaction within Context

People act within context Context provides constraints and expectations The context for interaction can be conceptualized as a

Hierarch composed of Activity

Tasks Steps (Actions)

The boundaries between these layers is fuzy

Hierarchy

Activity Is often associated with a high level goal that is desired and

satisfies a user intent. It has clear intrinsic value to the user

Task Is a element of an activity that is meaningful by itself. It has

little intrinsic value by itself, but it contributes to the attainment of the Activity

Step or Action Is an atomic component that by itself has no intrinsic value

to the user, but it contributes to task task

Interaction Design

Interaction design is about designing for the Steps. It often includes: Action Information

Steps are strung together to accomplish a Task Tasks in turn support an Activity

Context of Interaction

Activity Format Text

Tasks Font Paragraph Bullet & Numbering

Step – Within Bullets & Numbering Select Style Select color Select Size of Text Click on OK

Characteristics of Task Analysis

• Task analysis is a method we use to describe and represent how and to what end the functions of application or a website will be used

• It is systematic in nature• It is analytic rather the intuitive or speculative

• We often feel that we understand users task, but this understanding is frequently incomplete and wrong • e.g. the lath operator that used cloth pin to lock one of the safety

buttons


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Example of a Website


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Potential Users’ Tasks-Gain Understanding-Search for specific info.-Be enticed -Fill out forms-Contact a person


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NoNo

YesYes

Uses of Task Analysis

Describe how people currently perform specific tasks Describe how people in the future will perform a task Help develop training material Help identify good tasks (representative or critical) for

usability evaluation


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Motivation for Task Analysis• Ensure that what we design is congruent with users need

• Customers often forget their bank card in the ATM machine • Ensure compatibility with users’ characteristics

• Displaying date as Nov, 12, 2002 (for 12/11/02)• Ensure compatibility with users’ activity flow

• Do not forces the user to perform a task in an uncommon way such as reverse polish notation


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Expected Outcomes of Task Analysis

• A set of functional requirements• Functions that are needed and desired by end users

• A set of non-functional requirements for UI design• A Metaphor or a conceptual model

• Users describe contacts as items in a Rolodex• Specification of the task flow

• Focus areas for UI evaluation• Benchmark tasks for usability testing


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Extracting Conceptual Models


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Questions asked using TA

• What tasks do users perform and in what order• What tasks are desired• What happens when things go wrong• What tools are used in conjunction with task performance• Who else can impact task performance and how

• E.g., when using ATM consider the next person in line


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Include in Task Analysis

Start-up tasks Power-down tasks Maintenance tasks Miss use tasks


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Performing Task Analysis


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Task Analysis Focus

• Goal or Intent• What a single individual attempts to achieve

• Task sequence - How• The order in which tasks and subtasks are performed

• Task hierarchy - Why• How the components of a task relate to each other

• Task Actions• The individual steps and decisions that are involved in executing each

task

Gabriel Spitz

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Example – Task Hierarchy


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Hierarchical task Hierarchical task decomposition decomposition

describes what is describes what is done and why done and why

(the level above)(the level above)

Example – ProcedureGabriel SpitzGabriel Spitz

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Procedural Procedural analysis analysis

describes how a describes how a given task is given task is

executed and the executed and the decisions decisions involvedinvolved

Selecting Tasks

• Start with tasks that are meaningful by themselves• E.g. Replace a tire, not unbolt tire screws

• Select real tasks that users have faced• Make sure that selected tasks provide reasonable coverage of what

users need to do• Select mixture of simple and complex tasks• When we transition to the design stage

• Discard features that do not support users’ tasks• Add real task that exercise the features


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Structure of Task description• Specify the users

• Roles and their characteristics

• Specify where inputs come from and outputs go to• Working with other tools

• Reflect on the interest of potential users• Illustrate functionality in context of work users really want to do

• Focus on the system users will need• Not systems users say what they want• Remember, Users are not always right,

they often do not anticipate new technology accurately


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Describing Tasks

• Technology neutral - Say what the user wants to do, but not how the user would do it • E.g., contact dept head, but not send email to dept head• This allow comparing different design alternatives

• E.g., Letter, Email, Facebook, Skype, etc• Specific

• Forces us to consider how features work together• Include

• The information that the user need for a task• Both related and unrelated to software

• What the users sees and interacts with


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Using Tasks in design

• Write up description of task• Run by users and rest of the design team• Get more information where needed

• Rough out interface design• Major screens and functions (not too detailed)• Hand sketches

• Produce scenario for each task• What user has to do and what they would see• Step-by-step performance of the task

• use-case


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Gathering Task Analysis Data


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Methods for gathering Task Data

• Review documentation

• Observations – preferably in the workplace

• Interviews - preferably in the workplace

• Questionnaires and surveys


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Usage of Data Gathering Methods

• Documentation review• Develop a high level understanding of features, task, and procedures – what is

there• Observation

• Develop a detailed understanding of tasks, and procedures in the real world – How is it used

• Interview• Explore issues and develop use scenarios – What is missing

• Questionnaires• Gather specific information


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Once we Have the Data

• Describe the workflow graphically• This helps ensure that the task flow smoothly• All or most possibilities are accounted for• Tasks have a defined start and end points

• Verify the flow with end users


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Summary

• Answer questions before designing• Who, what, where , how often• Relationship between users and data• What other tools do users have• What happens when things go wrong

• Selecting tasks• Real tasks with reasonable functionality coverage

• What should tasks look like• Complete, specific tasks of what users want to do


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Documents

Task Analysis Lecture # 8 Gabriel Spitz 1. Key Points Task Analysis is a critical element of UI Design It describes what is a user doing or will