Lecture 9
Usability
of Health Informatics Applications
(Chapter 9)
http://www.csun.edu/~dn58412/IS531/IS531_SP16.html
Learning Objectives
1. Key Concepts: Human Factors, Ergonomics,
Human–Computer Interaction, and Usability.
2. Goals and Axioms of Usability
3. Human–Computer Interaction Frameworks
and Components
4. Usability Studies: Types, Tests, Methods,
and Process
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Key Concepts
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Key Concepts …
• HUMAN FACTORS
– Interactions between humans and
instruments/tools
• Ergonomics
– Human performance and interaction
with physical characteristics of tools/
machines/computers/systems
– Focus on design for safety, comfort, and
convenience
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…Key Concepts
• Human-computer Interaction (HIC)
– How people design, implement, evaluate
interactive computer systems in the
context of users’ tasks and works
• Usability
– How a product can be used to achieve
specific goals with effectiveness,
efficiency, and satisfaction
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Usability Goals …
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… Usability Goals
• Allowing users to focus on the task at
hand rather than on technology (= user
friendly)
• Effectiveness : usefulness and safety of
technology in reaching goals:
completeness, accuracy, cognitive match,
tasks/functions allocation between human
and computer
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…Usability Goals
• Efficiency of expenditure resources : time,
cost, productivity (error rates, learnability)
• User satisfaction of interactions with
systems: positive perceptions about
usability and perceived benefits lead to
application acceptance and use
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Axioms of Usability
• An early and central focus on users in
the design and development of systems
(understanding users in depth)
• Iterative design of application (allowing
user to evaluate the prototype and
provide feedback on systems
effectiveness and efficiency)
• Systematic usability measures (design
and evaluation in a recurring cycle,
feedback loop)
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Human–Computer
Interaction Frameworks
• UFuRT (multiple users, expertise /cognitive
characteristics, functions, functions/tasks
analysis)
• FITT framework (individual, tasks,
technology)
• HOT-fit (human, organization, technology-fit)
• Staggers Health Human–Computer
Interaction Framework (developmental
timelines, multiple contexts, multiple groups
of users, multiple technologies)
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Staggers HCI Frameworks
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Components of Staggers HCI
Framework:
Patient, Provider, and Computer Behaviors
• User interface
• Human and technology characteristics
• Task information exchange process (explicit or
implicit goal of task)
• Health context/environment (actual or virtual,
concrete of cultural/abstract)
• Developmental trajectory (new human and
technology characteristics emerge over time)
• Joint cognitive systems (systems development as
a plan with feedback and feed forward loops in a
cyclical model)
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Basic Usability Tests ...
• Heuristics Evaluation / Heuristic
Inspection Methods
– “Heuristic” = “Rule of thumb”
– Compare applications against accepted
guidelines for efficiency and
effectiveness
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…Basic Usability Tests
• Simplified Usability Tests
– Discount Usability Technique: use a
small numbers of users with “think
aloud” technique
• Cognitive Walkthrough
– Use “think aloud” technique to elicit
user’s thought processes while using an
existing products.
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Types of Usability Tests …
• Discovery Test to determine user needs
and requirements at the beginning of
SDLC
– Basic activities in this context
– Users cognitive process information
– Special considerations in this
environment
– Attributes for initial design
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…Types of Usability Tests
• Exploratory Test during early development
or redesign
– Value of basic functionality
– Intuitive navigation and information flow
– Required computer experience
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…Types of Usability Tests
• Assessment Test during midway
development
– User performance of selected tasks
– System consistency across modules
– Quick detection of critical information
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…Types of Usability Tests
• Validation Test
– Late in design cycle
– Test against predetermined standards,
benchmarks, performance measures
– How well modules integrated in the
whole system
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…Types of Usability Tests
• Comparison Test
– Assess different technologies
– Which application/technology is more
efficient
– Which design is more effective
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Usability Methods …
• Task Analysis
– Focus on cognitive processes,
observable user actions or interaction
with a system to reach user’s goals
– What users are doing or required to do
with a technology
– Tasks and behavioral actions between
users and computers.
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…Usability Methods
• Think-aloud Protocol
– Users will talk aloud as they interact
with an application
• Usability Questionnaires
– QUIS,
– Purdue Usability Questionnaire
– SUMI
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…Usability Methods
• Focused ethnographies
– Field study of people in cultural, social
settings
– Study social relationships and their
impacts on work
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Process of Conducting
Usability Tests …
• Define a clear purpose
– type, details, methods
• Assess constraints
– time, resources, technology, available
users
• Use an HCI framework to refine each
component.
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…Process of Conducting
Usability Tests
• Emphasize components of interest:
– control some framework components
– measure only what we want to know
• Match methods to purpose, constraints,
and framework assessment.
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Look into the Future
•
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New users (will include patients)
New types of information
New directives from agencies
New technologies
Ubiquitous computing
“Usability has a strong, often relationship
with clinical productivity, error rate, user
fatigue and user satisfaction – critical
factors for EMR adoption (HIMSS 2009)”
Cf. p.171, § 5
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