Goals of INFO3315
Learn about the range of techniques to:
• Understand users
• Establish requirements
• Brainstorm alternatives creatively
• Prototyping alternative
• Evaluate these
• Reflect on strengths and weaknesses of
prototypes
Learn how to actually use a core set of these
techniques
User Centred Design
•
•
•
•
•
•
Problem statements and situations of concern
Identifying user and their tasks
Requirements and one sentence statements
Systems analysis and design *
Creative exploration of concepts
Iterative prototype-based design
2
SSM
Soft Systems Methodology
Strategic
information
Systems
planning
Manage
Usability
evaluation
Job design and
technical support
Plan for systems
OSTA
Task Analysis
People
Work
Technology
Design
Implement
Usability
studies
Implementation
strategy
Manage
changes
Star
Multiview
Methods of user centred design (Eason in Preece)
User-centred design elements
• make users central
• users seen as people
– in an environment
– interacting with other people
• early testing and evaluation that involves
users
• design iteratively
4
Simple illustrative example
Thought experiment:
Thought experiment:
Large and busy railway system with
tickets sold solely by human ticket
sellers at each station.
Thought experiment:
Large and busy railway system with
tickets sold solely by human ticket
sellers at each station.
Brainstorm on the situation of
concern.
Elements of SSM analysis
Soft systems methodology
•
•
•
•
•
Stakeholders
Who are the users
Who else needs to be considered
What else must be considered
… CATWOE
9
SSM stages
real world - abstraction
1. The situation of concern
2. Expression of situation of concern
3. Root definitions (CATWOE)
4. Build conceptual models
5. Compare 4 with 2
6. Feasible and desirable changes
7. Action to improve situation
10
Situation of Concern
Thought experiment:
Large and busy railway system with
tickets sold solely by a person at each
station.
• There are long queues to buy tickets at peak hour.
• There is a huge salary bill for ticket sales staff.
• Being a ticket seller is considered a very dull job but is often
stressful in dealing with people who have been waiting a
long time.
• There is often a mismatch in tickets sold and cash each day.
• Elderly people really like buying tickets from a person.
• Complex ticket options mean that a ticket seller can be
really helpful.
• In times of high unemployment, ticket selling creates jobs.
• Ticket sellers also improve passengers’ sense of safety at
night and when there are few people around.
CATWOE
1. Clients
• Who is on the receiving end?
• What problem do they have now?
• How will they react to what you are
proposing?
• Who are the winners and losers?
CATWOE
2. Actors
• Who are the actors who will 'do the doing',
carrying out your solution?
• What is the impact on them?
• How might they react?
CATWOE
3. Transformation
• What is the process for transforming inputs
into outputs?
• What are the inputs? Where do they come
from?
• What are the outputs? Where do they go to?
• What are all the steps in between?
CATWOE
4. Weltanschauung (Worldview)
• What is the bigger picture into which the
situation fits?
• What is the real problem you are working on?
• What is the wider impact of any solution?
CATWOE
5. Owner
• Can they help you or stop you?
• What would cause them to get in your way?
• What would lead them to help you?
CATWOE
5. Owner
• Can they help you or stop you?
• What would cause them to get in your way?
• What would lead them to help you?
CATWOE
6. Environmental constraints
• What are the broader constraints that act on the
situation and your ideas?
• What are the ethical limits, the laws, financial
constraints, limited resources, regulations, and so
on?
• How might these constrain your solution?
• How can you get around them?
CATWOE-info3315
•
•
•
•
•
Checklist that is broadly useful
Helps broaden perspectives
Helps think about the people
And the other concerns
Informs definition of tighter interface and
system requirements
• And the people appropriate for evaluation
• Subject for A-4 sheet in exam
After identifying the transformation
that you believe will help address the
situation of concern
After identifying the transformation
that you believe will help address the
situation of concern
One sentence statement
One sentence statement (info3315)
A single sentence that states:
• The users of the system
• Description of the transformative interface
and system
• Training level of the users
• Time limits for completing task
One sentence statements (example)
A single sentence that states:
• The users of the system (A member of the general
public)
• Training level of the users (without any training)
• Description of the transformative interface and system
(will be able to buy a ticket at the automated ticket
selling machine)
• Time limits for completing task (within 1 minute)
A member of the general public without any training will
be able to buy a ticket at the automated ticket selling
machine within 1 minute.
Requirements
• Consider more user groups….
• Consider different levels of training…
• Consider different times associated with
these.
• Consider variability among people.
Requirements
• Consider more user groups….
– Elderly users
– Children
– Non-English speakers
– People who are blind…
• Consider different levels of training…
• Consider different times associated with
these.
• Consider variability among people.
One sentence statements (example)
A single sentence that states:
• The users of the system (A member of the general
public)
• Training level of the users (without any training)
• Description of the transformative interface and system
(will be able to buy a ticket at the automated ticket
selling machine)
• Time limits for completing task (within 1 minute)
A member of the general public without any training will
be able to buy a ticket at the automated ticket selling
machine within 1 minute.
Requirements
• Consider more user groups….
• Consider different levels of training…
–
–
–
–
–
Regular user (expert)
First time user (novice)
Intermittent user
Discretionary user
People familiar with other ticket systems (existing
mental models for buying tickets)
• Consider different times associated with these.
• Consider variability among people.
One sentence statements (example)
A single sentence that states:
• The users of the system (A member of the general
public)
• Training level of the users (without any training)
• Description of the transformative interface and system
(will be able to buy a ticket at the automated ticket
selling machine)
• Time limits for completing task (within 1 minute)
A member of the general public without any training will
be able to buy a ticket at the automated ticket selling
machine within 1 minute.
Requirements
• Consider more user groups….
• Consider different levels of training…
• Consider different times associated with
these.
• Consider variability among people.
– Normal distributions
One sentence statements (example)
A single sentence that states:
• The users of the system (A member of the general
public)
• Training level of the users (without any training)
• Description of the transformative interface and system
(will be able to buy a ticket at the automated ticket
selling machine)
• Time limits for completing task (within 1 minute)
90% of the members of the general public without any
training will be able to buy a ticket at the automated
ticket selling machine within 1 minute.
A note about times
• These include recovery from errors
• What if people fail to do the task at all?
• How does one test a requirement that starts
“90% of people…..”
Goals of INFO3315
Learn about the range of techniques to:
• Understand users
• Establish requirements
• Brainstorm alternatives creatively
• Prototyping alternative
• Evaluate these
• Reflect on strengths and weaknesses of
prototypes
Learn how to actually use a core set of these
techniques