Notes on evaluation and usability inspection, Baobab Health Trust, March 2014

Boabab Health, March 2014Harry Hochheiser, harryh@pitt.edu
Evaluation
Harry Hochheiser
University of Pittsburgh
Department of Biomedical Informatics
harryh@pitt.edu
+1 412 648 9300
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Baobab Health, March 2014Harry Hochheiser, harryh@pitt.edu
Why Evaluation?

Why Evaluation?
Show that it works?
Figure out what doesn’t work?
Figure out how to make things better?
Allocate resources effectively?
Support investment of resources
Justify scaling up

DECIDE Evaluation Framework

Preece, Rogers, Sharpe, Interaction Design, 2011
Determine the goals.
Explore the questions.
Choose the evaluation methods.
Identify the practical issues.
Decide how to deal with the ethical issues.
Evaluate, analyze, interpret and present the data.

Determine the goals
You already know the goals!
Decided during design
Costs
Quality
Time/Efficiency
Satisfaction
Materials,

Capital,

Revenue
Patient, Staff, MOH
Capacity,

Wait times,

Turnaround time
Safety

Waste Removal,

Best Practices
IMPROVE Safety,

Quality, Satisfaction

DECREASE Costs

Tradeoffs?
• Evaluation results may not be clear cut…
• Increased efficiency but decreased satisfaction?
• Increased quality but decreased efficiency?
• Decreased cost and decreased satisfaction?
• Mixed signals are not uncommon!

Evaluation Study types

Spectrum of Methods
Inspection Methods
Heuristic Evaluation
Cognitive Walkthrough
Lab Usability Studies
“think-aloud”
Comparative Empirical Studies
in situ evaluation
Quantitative and qualitative
Low
Cost

Low
Fidelity
High
Cost

High
Fidelity
Formative
Summative

No bright dividing line in process
Design
Fully-functional

Prototype

Paper

Prototype
Release
Usability Inspections
Usability Studies
Empirical User Studies, Case
Studies, Longitudinal Studies,
Acceptance Tests
Low
cost,
low
validity Higher
cost,
validity

Usability Assessments
• This is where we start talking about how to assess
usability!
• Goals - discuss usability measurements that can
• Inexpensively identify problems
• both potential and real
• Guide design
• ideally early, before deploymen

Goals of Usability Assessments
• Can users complete tasks?
• Appropriateness of mental models
• Comparative efficiency
• Subjective satisfaction
• How do we assess?

Usability Inspections
• “clean-room” static examination of usability
• Methodically scrutinize interfaces in search of potential
problems
• Pros:
– Inexpensive – no users, relatively easy
– Identify major issues at a relatively early stage
• Cons:
– May miss problems: generally find < 50%
– All results are hypothetical – don’t know which problems might
really lead to errors

Common Questions
•Who inspects?

•Background

•How many?

• Which tasks?

• How to interpret findings?

•Problems are not “real” problems experienced by users

•How important are they?

Two broad classes of usability
inspections
Heuristic Evaluations: How well does an interface conform to
guidelines for interface design?
Walkthroughs: Analytic examination of interface and interaction
requirements, usually informed by some model of the user
Many variants...

Baobab Health, March 2014Harry Hochheiser, harryh@pitt.eduHarry Hochheiser, harryh@pitt.edu Baobab Health, March 2014
Heuristic inspection
Usability experts
Domain experts
Combination? (Double experts)
Users should participate as users
when possible
3-5 experts? (Nielsen)
Or more...
Work alone, or in teams..
Walkthroughs
May require more cognitive
background
Domain expert feedback helpful
Conducted by a team?
Who inspects?

Heuristic inspections
Set tasks
Open-ended exploration
Walkthroughs
Generally, specific tasks
Tasks

Results 
Nielsen and Molich 1990 , Nielsen 1993
• Few false positives
• Find < 50% of errors
• “In general, we would expect aggregates of five
evaluators to find about two thirds of the usability
problems which is really quite good for an informal and
inexpensive technique like heuristic evaluation.”

Results 
Nielsen and Molich 1990
Source of the “you only need 5 evaluators” rule…
Hotly contested…

Which Evaluators? 
Nielsen, 1992
• “Double Experts” - Domain and Usability expertise – considered best
• Not always available – use some of each, or teams

When to conduct inspections?
Paper prototypes?
Working system?
Early and often…

Evaluators work alone
(except for when they work in teams)
Optional observer can help explain confusing issues and to
record issues.
Go through interface several times
overview and specific
Heuristic focus or task focus
Note discrepancies between interface and heuristic
Individual evaluators meet to aggregate results
Heuristic Evaluation Procedure

Nielsen's Heuristics

Nielsen, 1994 - http://www.nngroup.com/articles/ten-usability-heuristics/
• Visibility of system status
• Match between system and real world
• User control and freedom
• Consistency and standards
• Error prevention
• Recognition rather than recall
• Flexibility and efficiency of use
• Aesthetic and minimalist design
• Help users recognize, diagnose, and recover from errors
• Help and documentation


• Visibility of system status
•“The system should always keep users informed about what is going on, through
appropriate feedback within reasonable time”

• Match between system and real world
“The system should speak the users’ language, with words, phrases, and
concepts familiar to the user, rather than system-oriented terms. Follow real-world
conventions, making information appear in a natural and logical order.”

• User control and freedom
“Users often choose system functions by mistake and will need a clearly marked
"emergency exit" to leave the unwanted state without having to go through an extended
dialogue. Support undo and redo.”


• Consistency and standards

“Users should not have to wonder whether different words, situations,
or actions mean the same thing. Follow platform conventions.”
• Error prevention
“Even better than good error messages is a careful design which prevents a
problem from occurring in the first place. Either eliminate error-prone conditions or
check for them and present users with a confirmation option before they commit to the
action.”
• Recognition rather than recall
“Minimize the user's memory load by making objects, actions, and options visible.
The user should not have to remember information from one part of the dialogue to
another. Instructions for use of the system should be visible or easily retrievable
whenever appropriate.”


• Flexibility and efficiency of use
“Accelerators -- unseen by the novice user -- may often speed up the
interaction for the expert user such that the system can cater to both
inexperienced and experienced users. Allow users to tailor frequent
actions.”
• Aesthetic and minimalist design
•
“Dialogues should not contain information which is irrelevant or rarely
needed. Every extra unit of information in a dialogue competes with the
relevant units of information and diminishes their relative visibility.”


• Help users recognize, diagnose, and recover from errors
“Error messages should be expressed in plain language (no codes), precisely
indicate the problem, and constructively suggest a solution.”
• Help and documentation
“Even though it is better if the system can be used without documentation, it
may be necessary to provide help and documentation. Any such information should be
easy to search, focused on the user's task, list concrete steps to be carried out, and
not be too large.”

Recording Heuristic Violations
• Which Heuristic
• Description
• Severity
• Proposed revisions

Use severity judgments to prioritize fixes
Frequency of problem
Impact of problem
Persistence – will users be repeatedly bothered?
Multiple independent raters increase reliability
Bigger questions – does this design work at all?
As with usability studies, try to generalize
Don't solve lots of small problems if the design is inherently problematic
Interpretation

Making use of heuristic evaluation
results?
●
Have member of development team present during
inspection?
Can be done with usability studies and other inspections as well
They should observe, not analyze
●
Debriefing session to explore fixes
Consider redesigns where appropriate.

Other Inspection Methods

http://www.useit.com/papers/heuristic/inspection_summary.html
Heuristic estimation – compare interfaces
Feature Inspection – look for long sequences
of operations, unnatural sequences,
those requiring extensive skill...
Consistency inspection – compare designs for consistency
Standards Inspection

Which Heuristics?
• Multiple versions of Nielsen’s list
• Other versions
– Special cases?
• More heuristics – more focus
– ..but less study
• Too many heuristics – cumbersome, complicated

Web Usability Heuristics 
http://www.andybudd.com/archives/2007/01/
heuristics_for_modern_web_application_development/index.htm
• Design for user expectations
• Clarity
• Minimize Unnecessary Complexity and Cognitive Load
• Efficiency and Task Completion
• Provide Users with Context
• Consistency and Standards
• Prevent Errors
• Help users, notice, understand, and recover from errors
• Promote a pleasurable and positive web experience

Using usability heuristics to evaluate patient safety of
medical devices 
Zhang, et al. 2003
• Nielsen heuristics + Shneiderman’s 8 golden rules
• Revised and clarified
• New severity ratings
• Demonstrations of use…
– … but less study than Nielsen’s list

Zhang, et al. 2003 - Heuristics
• Consistency
• Visibility
• Match
• Minimalist
• Memory load
• Feedback
• Flexibility
• Messages (errors)
• Errors (prevention)
• Closure
• Language
• Control
• Document
Severity Rating
0. No problem
1. Cosmetic
2. Minor
3. Major
4. Catastrophe

Zhang, et al. 2003 - Heuristics
• Severity rating
• “As a guideline for rating the problems, we consider the
proportion of users who will experience it, the impact it
will have on their experience with the product, and
whether the usability problem will be a problem only the
first time they encounter it, or whether it will
persistently bother them. A persistent problem with a
major impact that most users will encounter will get
the highest severity rating.”
• What about rare but potentially catastrophic
problems?

Assessing the usability of a telemedicine-based
Medication Delivery Unit for older adults through
inspection methods 
Ligons, et al. 2011
●
EMMA: The Electronic
Medication Management
Assistant (INRangeSystems, Aloona
PA)
●
Electronic medication
delivery + wireless
communication with pharmacy
●
Track adherence
●
Adjust dosage
●
Touch screen interface

Medication Delivery Unit … 
Ligons, et al. 2011
• Goal: use MDUs to improve adherence among older
patients
• Concern – touch-screen might be hard to use
– Calibration of touch
– Low vision or blindness - difficulty seeing screen/reading?
– Cognitive challenges – understanding use?
• Use Heuristic evaluation for first-pass investigation of
usability
– Question – “Can users use the system?”, not
“How can we improve the system?”

Ligons, et al. 2011
NLM guidelines for website
design for older adults
• User only sans-serif font,
12-14 point, medium or bold
weight, double-spaced, left-
justified
• Avoid blue, yellow, and green, in
close proximity
• Use light background with dark
text or dark backgrounds with
light text
• Modified Nielsen (1990)
heuristics
Simple and Natural Dialog
Speak the user’s language
Minimize memory load
Be consistent
Provide Feedback
Provide clearly marked exits
User good error messages
Prevent errors
Provide shortcuts

Assessing the usability of a telemedicine-based  
Ligons, et al. 2011
• Explore interface with respect to each heuristic
– Multiple passes

Assessing the usability of a 
telemedicine-based Medication  
Delivery Unit … 
Ligons, et al. 2011
• Minimize memory load - major issues
– Confusing buttons complicate access to help system
– “Drop” menu for advance indications doesn’t include displays of
appropriate dates and medications
• Be Consistent – minor issues
– “back” button vs. “cancel” buttons
– “medication drops” vs. “advance drops” on different screens
• Provide Feedback – medium
– No feedback when buttons are pressed
– Slow response

Ligons, et al. 2011
• Prevent Errors – medium
– Small buttons with low tolerance
– Complicated process of loading and unloading medication packs
• Typeface
– Small fonts for on-screen medication and information on
blister packs

Usability Evaluation of an Electronic Medication
Administration Record (eMAR) Application 
Guo, et al. 2011
• Medication Administration Record - record of drug delivery
• eMAR tasks
– Access to drug information, policies, and procedures related to
meds
– Context-specific patient clinical results
– Facilitate communication between nurses and pharmacists
– Verification of the five “rights” (patient, drug, dose, route, and
time)
• Heuristic Evaluation for usability
• Using Zhang’s heuristics and severity ratings

Electronic Medication Administration Record (eMAR)
Application 
Guo, et al. 2011

Heuristic evaluation of eMAR 
Guo, et al. 2011
• Tasks
– Login
– Order and modify medication
– Verify medication orders
– Access drug references
– Administer medication
– Edit eMAR
– Generate reports and review
• Procedure
– Train evaluators
– Conduct evaluation
– Calculate agreement
– Build consensus
– Review with staff – conduct tasks

Guo, et al. 2011
• Observations
– classified by heuristic,
– grouped into usability problems
– Organized by task

Guo, et al. 2011

Notes on evaluation and usability inspection, Baobab Health Trust, March 2014

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Notes on evaluation and usability inspection, Baobab Health Trust, March 2014