The Science of Cognition and Human-Computer Interaction in

Health Care

Vimla L. Patel, PhD, DSc

Cognitive Studies in Medicine:

Centre for Medical Education

McGill University

Montreal, Canada

Evolution of Medical Informatics: Importance of Interface Design

Sophistication of Technology

Unfilled Technology

Need

Risk of Excess Functionality

Technology Delivers Basic

Need

Sophistication of Typical User

High

Low High

Low

Technology is “good enough”

User Experience Dominates

Technology Matched to

Increasing User Sophistication

System Complexity

Masked from Lay User

?CurrentTrend

What is the User Interface?

InputLanguage

OutputLanguage

CommunicationProtocol

Those aspects of the system with which the human user comes in contact

Examples: ATM, point-and-click navigation in web browsers...

Ways to Deal with User Interface Design

• Focus on the way the user has traditionally functioned

• Focus on optimizing the interface and requiring user adaptation

• Study Interaction to see:

• what aspects of the user can change

• what aspects of the system can change

Dimensions of Human Computer Interaction (HCI)

Technological

• Hardware and Software Advances

Cognitive

• Representation• Knowledge Organization• Reasoning and Strategies

Cognitive Aspects of Interface Design

Human Processes:

• Comprehension• Navigation • Communication

These Affect:

• Learning• Performance

Comprehension andLevels of Meaning

Comprehension andLevels of Meaning

• Text-based Model - Surface• Syntax / Semantics• Generation of Local Inferences• Propositions

• Situation Model - Deep• Representation of Events, Actions and Persons

in Context• Conceptual• Generation of High-Level Inferences• Pragmatics: Context-Bound Inferences

Representation ofClinical Information

Interpretation(in Context)

Comprehension PRIORKNOWLEDGE

Instantiation

ConceptuallyDriven Process

NEW KNOWLEDGEGeneralization

CLINICAL DATA

Data-driven Process

Comprehension Processes

THOUGHTSAND IDEAS

PROPOSITIONALREPRESENTATION

text-based model

Propositional Analysis(a form of representation of asemantic network in memory)

NATURALLANGUAGE

expressed through

Semantic Network(relationships between

propositions)

CONCEPTUALREPRESENTATION

situational model

Semantic Representation of Natural Language Analysis

SYSTEMSLEVEL

DIAGNOSTICLEVEL

INTERMEDIATECONSTRUCT

FINDINGLEVEL

OBSERVATIONLEVEL

C1 C2

D1 D2 D3

FA1 FA2 FA3 FA4 FA5

F1 F2 F3 F4 F5 F6 F7 F8 F9

O7

O8

O9

O10

O11

O12

O1

O2

O3

O4

O5

O6

+ + +

Structure ofMedical

Knowledge in Problem Solving

• Learning to use technology

• “Effects with” technology

• Learning beyond technology

• “Effects of” technology

Cognition and HCI

Human-Machine Cognition

• Human experts skip steps during the reasoning process

• Decision-support systems go through every step methodically in the logical process

• This distinction can lead to cognitive dissonance between users and machines

Usability

• Usability Testing

• Testing of ease of use must be theory-driven

• Usability Inspection

• Cognitive walkthrough as a method for gaining insight into user perceptions and misconceptions

Usability InspectionUse of Medline

• Cognitive Walkthrough:

• Assess usability for specific tasks • Usability analyst steps through system interface methodically

• Question:

• Can we anticipate user goals, actions and potential problems in using an information retrieval system like Medline?

Cognitive Walkthrough - Medline Search

TASK: To find articles from Medline related to pregnancy and diabetes

Goal 1: Find articles related to diabetes

Sub-Goal: Do a keyword search on diabetes

Action: enter key combination <control R>

System Response: “Enter a word or phrase”

Action: type in diabetes and press enter

System Response: Returns 22998 entries

Potential Problem: List too extensive

Goal 2: Find articles on pregnancy

As above (Goal 1)

Goal 3: Merge list of entries on diabetes and pregnancy

Potential Problem: Subject must map term “combine” to action “merge”

Sub-Goal: Combine data sets (diabetes and pregnancy)

Action: Key combination <control n>

System Response: Screen with 2 sets and instructions “Use spacebar to select at least two sets to combine and then press <Enter>”

Action: Scroll to diabetes, press space-bar

Action: Scroll to pregnancy, press space-bar

Action: Press <enter>

System Response: Combine sets screen: Choose Boolean connective “and” or “or”

Potential Problem: Choice of connectives

Action: Select “and” and press <enter>

….

Results

• Numerous potential problems• To perform the task required:

• 12 sub-goals• 22 actions• 9 transitions between screens

• The goal-action analysis shows the cognitive load put on the user in doing simple tasks

Impact of a CPR System on Human Cognition

• Studies of transition from paper records to CPR and back to paper record

• Impact on knowledge organization, reasoning, and learning

Changes in Reasoning Patterns

• Paper Records• Data driven reasoning

• Computer-Based Record• Problem directed reasoning

• Return to Paper Record after CPR• Problem Directed Reasoning

• Residual effect of CPR on learning (after CPR removed)

Changes in Information Management and CPR Use

0

20

40

60

80

100

Pre-CPR CPR

RelevantIrrelevant

% of Record Contents

Multiple Hypotheses

Diagnostic Reasoning Using CPRHypothesesPatient Data

Diagnostic Reasoning Using Paper Record

Patient Data

1. Chief Complaint 10 282. Past Medical History 13 133. Life Style 33 194. Psychological Profile 10 115. Family History 7 146. History of Present Illness 55 277. Review of Systems 52 88. Physical Examination 60 559. Diagnosis 14 910. Investigation 29 1711. Treatment 21 24

Total Entries 304 225

Category of Information Hand-WrittenPatient Record

Computer-BasedPatient Record

Information in CPR and Hand-Written Records

• Investigate communication between humans, between machines, and between humans and machines

• Understand

• How people think• analog processing, imprecise

• How machines think• digital processing, precise

• Capitalize on individual and group expertise

Collaboration and Distributed Cognition

C

A B E

G

F

H

J

I ML

D

K

Sociometric Analysis of Email Communication Patterns

Stanford

DSG

Columbia

MGH

InterMedCentral

Stanford Columbia

MGH

C

AB E

F

ML

D

K

Email Communication PatternsEpisode 1: Vocabulary Server and Guidelines

(Jan-Feb 95)

INTERMED

CENTRAL

Stanford

DSG

Columbia

MGH

C

AB E

G

F

H

J

I

D

K

Email Communication PatternsEpisode 2: Guidelines Representation

(Feb-Mar 96)

INTERMED

CENTRAL

Evaluation of PatCIS

Interact via Internet

PatCIS

4. Log File - System Usage Database (e.g. infobutton)

5. On-line Questionnaire

Data(from pilot study)

3. E-mail(to evaluators & designers)

1. Video BasedUsability Testing (“think aloud”)

2. Telephone Interviews (audiotape)

Patient

Patient-System Interaction

Lay people’s conceptual model of:• Normal health and illness

• How people reason about health• How technology works

• Study activities of people as they interact with systems

Reasoning Patterns, Data Entry

• Organization of knowledge differs among lay and professionals

• Reasoning patterns of professionals and patients are also different

Patients’ Use of Concepts in Explanations of their Decisions about Diabetes

Cytryn & Patel (1998)

0

25

50

75

100

Mea

n P

erce

nt

Fre

qu

ency

Blood GlucoseLevel

Diet, Activity,Stress

Insulin HypoglycemicReaction

Type of Information

Patients

Physicians

Data Entered into the System Accuratelyby Patients and Physicians

Cytryn & Patel (1998)

Reasoning Pattern: Patient

Instruction:Explain decision

Response:“Well let’s say if I’ll eat a pound of candies my sugar will go sky high and it might even cause a stroke!”

Cytryn & Patel (1998)

ComplicationsIncreased

Carbohydrate IntakeIncreased BloodGlucose Level

COND

(lead to)

COND

Reasoning Pattern: PhysicianInstruction:

Interpret Scenario

Response:“A fasting blood sugar of 160 pretty much says she’s diabetic. The postprandial is 200 also tells us she’s diabetic. She’s overweight, that’s already got me thinking that if she’s insulin resistant, then I might be able to improve that by having her lose weight.”

Overweight

Fasting Blood Glucose

Postprandial Blood Glucose Insulin Resistant

Diabetes

COND

COND

COND

COND

Cytryn & Patel (1998)

Reprise: Reasoning Patterns

Overweight

Fasting Blood Glucose

Postprandial Blood Glucose Insulin Resistant

Diabetes

COND

COND

COND

COND

Cytryn & Patel (1998)

ComplicationsIncreased

Carbohydrate IntakeIncreased BloodGlucose Level

COND

(lead to)

COND

Patient

Physician

Summing Up: What’s Next?

• Cognitive and social sciences are mandatory for design and implementation of UI’s

• Must have deep understanding of what people do and how they reason about it before developing systems that support those activities

• Must have better understanding of how people think about the systems they use (acknowledging different expert and lay models)

• Recognize the movement towards distributed systems, with human beings as heuristically-driven, analogue thinkers partnering with precise digital systems.

More Future Challenges

• We will move to greater complexity in systems, but need to consider smaller, manageable tasks and thus less complex systems as experienced by users

• Recognize relation between education and training

• Training is not enough• Must educate to support training

Discussion/Dialogue

Seminars, Community-based groups

Education (Knowledge)

Ambiguous (incomplete, inconsistent)

Decision Making

Typical(Certain)

Guidelines Action

Training (Action)

Linked to other Information Systems

Easily & Quickly AccessibleUser Interface

Education to Support Training

Update

Analysis and Results

The Key Role of Theory in Generating Design Recommendations

Data

Recommendations

XX

Interpretation

Generalize

Customization to Case

TheoryGuides