Lecture 9 Usability of Health Informatics Applications (Chapter 9)

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Lecture 9Usability

of Health Informatics Applications (Chapter 9)

Learning ObjectivesLearning Objectives

1. Key Concepts: Human Factors, Ergonomics, Human–Computer Interaction, and Usability.

2. Goals and Axioms of Usability3. Human–Computer Interaction Frameworks

and Components4. Usability Studies: Types, Tests, Methods, and

Process

IS 531 : Lecture 9 2

Key ConceptsKey Concepts


Key Concepts …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


……Key ConceptsKey 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


Usability Goals …Usability Goals …


… … Usability GoalsUsability Goals

• Allowing users to focus on the task at hand rather than on technology

• Effectiveness : usefulness and safety of technology in reaching goals: completeness, accuracy, cognitive match, tasks/functions allocation between human and computer


……Usability GoalsUsability 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


Axioms of UsabilityAxioms 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)

Human–Computer Human–Computer Interaction FrameworksInteraction 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)


Staggers HCI FrameworksStaggers HCI Frameworks


Components of Staggers HCI Components of Staggers HCI Framework:Framework:

Patient, Provider, and Computer BehaviorsPatient, 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)


Basic Usability Tests ...Basic Usability Tests ...

• Heuristics Evaluation / Heuristic Inspection Methods– “Heuristic” = “Rule of thumb”– Compare applications against accepted

guidelines for efficiency and effectiveness


……Basic Usability TestsBasic 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.


Types of Usability Tests …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


……Types of Usability TestsTypes of Usability Tests

• Exploratory Test during early development or redesign– Value of basic functionality – Intuitive navigation and information flow– Required computer experience



• Assessment Test during midway development– User performance of selected tasks– System consistency across modules– Quick detection of critical information



• Validation Test – Late in design cycle– Test against predetermined standards,

benchmarks, performance measures – How well modules integrated in the

whole system



• Comparison Test– Assess different technologies– Which application/technology is more

efficient – Which design is more effective


Usability Methods …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.


……Usability MethodsUsability Methods

• Think-aloud Protocol– Users will talk aloud as they interact

with an application• Usability Questionnaires

– QUIS, – Purdue Usability Questionnaire– SUMI


……Usability MethodsUsability Methods

• Focused ethnographies– Field study of people in cultural, social

settings– Study social relationships and their

impacts on work


Process of Conducting Process of Conducting Usability Tests …Usability Tests …

• Define a clear purpose– type, details, methods

• Assess constraints– time, resources, technology, available

users• Use an HCI framework to refine each

component.


……Process of Conducting Process of Conducting Usability TestsUsability Tests

• Emphasize components of interest: – control some framework components– measure only what we want to know

• Match methods to purpose, constraints, and framework assessment.


Look into the FutureLook into the Future

• 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


Lecture 9 Usability of Health Informatics Applications (Chapter 9)

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