software and lifecycle the star modelliacs.leidenuniv.nl/~verbeekfj/courses/hci/hci2014-09.pdf ·...

Human Computer Interaction 2014, Lecture 9 1

LECTURE 9

SOCIO-TECHNICAL ANALYSIS,

SERVICE DESIGN,

TASK ANALYSIS

October 2th, 2014

1human computer interaction 2014, fjv

Recapitulation Lecture #8

• Software lifecycle

• Effort spend on design

• HCI lifecycle

– Waterfall,

– Spiral,

– Star Model

• Perspective for HCI: User Centered design

– User analysis, Task analysis

– Prototyping, Dialog analysis

– Evaluation, Usability testing

human computer interaction 2014, fjv 2

Software and Lifecycle

• Key issues:

– Verification: make sure your are developing the

system right (requirements)

– Validation: make sure you develop the right

system (customer/user)

– Iteration: improve the design from previous

solutions/synthesis

– Evaluation: incorporate reviews of design by

developers and future users

– Pivot on the user


The Star Model

4

Prototyping

Implementation

Conceptual design /

Formal design

EvaluationRequirements

specifications

Task analysis /

Functional analysis

ideaproblem

human computer interaction 2014, fjv


User Analysis

• Methodology

– Stakeholders

– Persona, Scenario

– Problem statement

• Analysis techniques

– Questionaires

– Site Visits, Observations

– Ect.

• Is the situation always that straightforward?


New Interactions

• New interactions must make you feel

uncomfortable with previous interactions

• Direct manipulation:

– Mouse based, Pointing device based

– Screen based

– Gestures?

• What would we experience as new …


7

www.dontclick.it


Example from HCI 2013

• Project for Augmentation

• Can we make an augmented interactive fish.

• Technical aspects need be solved.

– Shadow casting

– Projection

• Users have to sort out how it works.

• Realized with the vvvv environment



The Augmented Zebrafish


Example: Menu in text webpages


• Long pages

• Mental model of content

• Minimizes within page links

• Minimizes scrolling

Accordion Menu – folds out like an accordion

• Increases congnitive load

• Increases interaction costs

• Hides information

• Complicates printing

Long P

ages

–a P

roble

m ?


COMMUNITY DRIVEN

SYSTEMS ANALYSIS

Socio-Organizational Analysis



Stakeholders (from lecture 8)

• Anyone affected by success/failure of system.

– Primary stakeholders

• End users

– Secondary stakeholders

• Input/output related; do not use system, get output …

– Tertiary stakeholders

• Management level, i.e. directly affected

• Customers

• Competitors

– Facilitating

• Design, development, maintenance


Stakeholders?

• There are different stakeholders to a problem– Different requirements

• Result in different– Usability requirements

– Acceptability requirements

• Important to capture stakeholder requirements– Different techniques: OSTA, CUSTOM, SSM

– Direct involvement: Participatory Design, ETHICS


Socio-Organizational Analysis

• CUSTOM (User Skills and Task Match)

– Focus on the Stakeholders (requirements)

– 6 stages

• OSTA (Open System Task Analysis)

– Focus on the tasks in the system (users’goals)

– 8 stages

• SSM (Soft Systems Methodology)

– No assumption; Complete picture of system

– 7 stages


CUSTOM: User Skills & Task Match

Six stage process - focus on stakeholders (1-3)

1. describe organizational context, including:

primary goals,

physical characteristics,

political and economic background

2. identify and describe stakeholders, including:

personal issues,

role in the organization and job

3. identify and describe work-groups whether

formally constituted or not



CUSTOM: User Skills & Task Match

Six stage process - focus on tasks (4-6)

4. identify and describe task–object pairs

i.e. tasks to be performed and objects used

5. identify stakeholder needs,

- stages 2–4 described in terms of both current

and proposed system

- stakeholder needs are identified from the

differences between the two

6. consolidate and check stakeholder requirements

against earlier criteria


OSTA: Open System Task Analysis

Consequences introduction technology on workfloor

Eight stages model - focus on task

1. primary task identified in terms of users’ goals

2. task inputs to system identified

3. external environment into which the system will be

introduced is described, including:

physical,

economic and

political aspects

4. transformation processes within the system are

described in terms of actions performed on or with

objects


OSTA: Open System Task Analysis

Eight stage model - focus on task

5. social system is analyzed, considering existing internal

and external work-groups and relationships

6. technical system is described in terms of configuration

and integration with other systems

7. performance satisfaction criteria are established,

indicating social and technical requirements of system

8. new technical system is specified

OSTA uses Flow-Charts – Text Descriptors


Soft Systems Development

• Holistic view on systems design– Technology and People are components

– Not a focus on a solution

– Descriptive understanding of situation: Rich Picture

– Captures workflow, Conflicts

• Useful approach for HCI

• Focuses on Planning

• Directs on understanding wholeHuman ~ Computer system

• Consists of 7 stages




1. Problem

situation (unstructured)

2. Problem

situation expressed

3. Root definitions

of relevant systems

7. Action(s) to

improve situation

6. Feasible &

desirable changes

5. Comparison 4-2

4. Building

conceptual models

Real World

Abstract World


SSM - stage 1-2

• Rich expression of problem situation

• Meetings stakeholders (parties involved)

• Different stakeholders, different views

– Purpose of the system

– Perspective to system, emphasize aspects

– Not necessarily contradictory


Example SSM Stage 1-2

• Efficiency in education: Government considers implementing system of standard assessment tests at schools, ages 7,11,14,16.

• Results are published: enable comparison

• Question?

– Stakeholders,

– Purpose from perspective Government. ?

• Stakeholders : – Teachers, parents, children, educationalists, gov.officials, prospective parents

& employers

• Purpose: increase efficiency & allow comparison of performance between schools



1. Problem

situation (unstructured)

2. Problem

situation expressed

3. Root definitions

of relevant systems

7. Action(s) to

improve situation

6. Feasible &

desirable changes

5. Comparison 4-2

4. Building

conceptual models

Real World

Abstract World



SSM - stage 3

• Formulation of "good" Root Definitions decisive to the creation of the conceptual model in Stage 4.

• Root Definition is tested against CATWOE, that defines a check-list for:

• Customer,

• Actors,

• Transformation process,

• Weltanschauwung (worldview),

• Owner, and

• Environment.


Example SSM Stage 3

• Question? Give Root definition for school system using CATWOE

• C(lients)– Teachers, schoolchildren, parents, government, educationalists

• A(ctors)– Teachers, schoolchildren, assessment makers, government

• T(ransformation)– From input to children to figures showing score (age) per school

• W(eltanschauwung)– Test feasible/desirable method of improving efficiency

• O(wner): Government• E(nvironment): Schools in education system


Rich Picture with CATWOE


Development of

a system for health

services.

Analysis by NIH

SSM - stage 4

Conceptual model

• A logical expansion of the Root Definition is madeinto the minimum necessary set of activities todefine what the system actually does at a particularresolution level.

• The qualitative modelling process uses pictures and diagrams to define and communicate structure, logic, ideas and relationships.

• The Conceptual Model should be expressed by verbs.



SSM - stage 5

Comparison of the Conceptual Model with the

real world is undertaken by comparing each of

the second resolution activities within the

model with the real world problem situation.


SSM - Merits

• Stresses understanding situation

• Does not stress understanding problem

– Problem might be caused by current system

– Perceived problem; Scope wide as possible …

• Modelling away from “real world”

– Should not representing what happens now

– Seek solution outside current domain …

– Creative


Others

• ETHICS (Effective Technical & Human Computer- based Systems)

– Relates to socio-technical approaches

– Stakeholders are participants in the development

– Focuses on Acceptance of the system

– Maximizes knowledge of stakeholders

• Participatory design

– Involves users early on in design phase

– Brainstorming sessions

– Lo-Fi prototyping

– Different techniques like PICTIVE/CARD

human computer interaction 2014, fjv31

SERVICE DESIGN

Designing coherent sequences of products ...



Service Design

• Not just designing a Device

• Not just designing Software

• Design experience

– Coherence

– Satisfying

• Products:

a network of experiences/combinations


e.g. Service Design


Touch-Points Example

• Touch-Point is an encounter with the Service

– Interaction in service chain

– Demonstrate consistency

– Interactions are defined in Service Design

• iTunes

– iPod

– iTunes software, local collection

– iTunes store

– Share in home network

– Share Multiple devices (iPhone, MacBook, PC ...)


Brand

• Brand tells YOU what you Interact with

• Same entity = Service Provider

• Design

– Provide resources for people~provider interaction

– Service is more Intangible than Product

– Relates to life-style

• Service

– Rooted in life-style

– Interactivity in time/place - touchpoints



Design by Lifestyle: DbL

• DbL is an approach to design that aims to deal with service HCI in the 2010s.

• Key feature of designing for new environments– Cannot ‘gather’ requirements from observing people, – Cannot interviewing people using existing systems.

• LifeStyle– no existing systems– no requirements aiming to meet a particular need.

• Designers need to– create experiences and new services– understand the characteristics of the people who will

use their new services and engage with the new experiences.


LifeStyle

• Lifestyles focuses on the ways in which people lead their lives, on their aspirations rather than their intentions, on their values and on their search for identity. • details of lifestyles and

• activities associated with lifestyles,

• vary across different domains and environments.

• Lifestyle notion• constructed to be more abstract than personas and scenarios.

• Lifestyle• presence of services (touch-points)

• the presence of others (both real and virtual)

• interactions appropriate to time, place and circumstance.

• Link to Time-Space matrix from Groupware (lecture 12)


Envisionment and DbL

• 4 Enabling Envisionment techniques are used

– Help in Rapid Prototyping of ideas.

– Video Scenarios (example, uni.me, Lecture 8)

– Style Sketches,

– Software demos

– Wizard of Oz.

• Necessary engaging people with evolving

design


Example Service Design



TASK ANALYSIS

HCI is task oriented, therefore Analysis for task orientation ...


Task Analysis

• Task (definition)– Something a user undertakes to achieve something

– To HCI, extremely meaningful

• Effective (G)UI design dependent on knowledge of:– Frequency of use

– Ordering

– Importance of a task

• HCI focus on Task Analysis– Decomposition

– Ordering

– Assignment (computer – human – interactions)42human computer interaction 2014, fjv

Task Analysis

• Logical representation of task sequence

• Introduces domain knowledge

• Grammar based task notation

• Graphical based task notation (structure chart)

• TASK:

– A goal together with some ordered set of actions

– Ordering refers to the logic

• TASK analysis

– Mono-teleological (oriented to one goal)


Task Analysis

44

‘ Task Analysis is the process of analysing the

way people perform their jobs and it is important

to the software designer because a major part of

the design will focus on supporting the jobs

people do.’

[McCauley, 1995]



Task Analysis

• Organization of user interaction with system into:

– Goals

– Methods

– Operators

– GOMS (see later lecture): Cognitive Task Analysis

• Constructs a model for user/system interaction

– Hierarchical decomposition

– Emphasis on sequence of operations


Methods for Task Analysis

• Hierarchical task decomposition– Tasks, Subtasks, Actions, Plans

• Knowledge based analysis– Organization of knowledge

– All objects and actions in a task

– Building taxonomy of relations

– TDH: task descriptive hierarchy

– Build rules of formal logic

• Entity-Relationship based analysis– Cataloging objects and actions

– Emphasis on relationships

– Typical in OO-design, less accounting environment


Hierarchical Task Analysis (1)

• 0. Borrowing a book from the library

– 1. Go to the library

– 2. Find the book of interest

• 2.1 access the library catalog

• 2.2 access the search system

• 2.3 enter search criteria

• 2.4 identify required book

• 2.5 make a note of location

– 3. Go the correct shelf and retrieve book

– 4. Take book to checkout counter



• Decomposition has resulted in plans

• Plans are scenarios of dedicated interaction

• Plan arranged according to subtasks

• Plan: how action sequence is applied in a

situation

– Plan 0: do 1-3-4

• If book not there: do 2-3-4

– Plan 2: do 2.1-2.4-2.5

• If book no identified: do 2.2-2.3-2.4-2.5



Types of plan

Plan = structured path to achieve the goal.

fixed sequence - e.g. 1.1 then 1.2 then 1.3

optional tasks - if <condition> then action

wait for events - when <condition> then 1.4; time involved

cycles - do <action 1 .. N> while <condition>; loop

time-sharing - do <action>; at the same time ... (and do)

discretionary - do any of <action a>,<action b> or <action > in any order

mixtures - most plans involve several of the above


Allocation of Function

• What task done by human

– No support from computer system

• What task done by both computer / human

– Really shared task (INTERACTION)

• What is just done by the computer

– Nearly no human intervention /interaction

– What is a computer good at!


Human ~ Computer Tasks



Hierarchical task decomposition

• often using structure chart

• decompose in tasks, subtasks, and actions

• plan: sequence of subtasks or actions (TDH)

• TA should coincide with user’s mental model

• task allocation important



Task Decomposition

• What questions need to be asked:

53

TaskWhat happens

before?

What happens

next?

What

subtasks?

Why?


What Knowledge is required!


• Based on graphical representation of task decomposition

• in task hierarchy diagram (THD)

– describes tasks in hierarchy of actions and plans

1. Identify major tasks

2. Breakdown tasks

3. Draw tasks/subtasks as layered diagram

4. Continue decomposition

5. Ask someone to check your analysis

ACTION: simple task, not iterated.


Hierarchical Task Analysis


Hierarchical task analysis for creation of reading website



Case Study “Fast Ferries”

• Design a computerized system to support fast and efficient on-line enquiries and bookings at each sales position: reservation system

• Supported activity

– Sales to general public by staff in travel agency

• Users

– Staff in travel agency

• Level of Support

– Detailed enquiry; Information processing; Validation

• Form of solution

– On line system


Task Hierarchy Diagram (THD)

58

Serve customer

Make

enquiry

Make

booking

Perform other

Service

routes sailings Avail-

ability

Accomo-

dation

Enter

detailConfirm

detail

Accept

deposit

Record

deposit

Check


THD with function allocation

59

1 Serve customer

1 Make

enquiry

2 Make

booking

3 Perform

other Service

1

Routes

2

Sailings

3 Avail-

ability

4 Acco-

modation

1 Enter

detail2 Confirm

detail

3 Accept

deposit

4 Record

deposit

Check


User-Centred Design Overview

• Design requires assessment

– Establish

• who are users

• what are their goals

• what tasks need to be performed

– Task Analysis

• Characterize what steps users need to take

• Create scenarios of actual use

• Decide which users and tasks to support

• Design based on user characteristics and tasks

• Evaluation

– Test interface by “walking through” tasks

– Typically before implementation



Review #9b

• Task analysis

• To Do

• Cognitive analysis

• Dialogue analysis

• Usability

• Envisionment – Prototyping

• Evaluation


software and lifecycle the star modelliacs.leidenuniv.nl/~verbeekfj/courses/hci/hci2014-09.pdf ·...

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