Usability

Architecture of Learning Environments E19.2017 Usability Research

Why is Usability Important?
Technologies are changing very rapidly and usability assurance needs to keep pace.
Productivity- poor usability hinders productivity
The user becomes frustrated, will go elsewhere

Definition: Usability as a Dialogue
“ (a) system’s usability is the extent to which it supports the potential for people who work with it to understand it, to learn, and to make changes…
The technology itself, even when it is not intended as a communications product, serves as a communication medium between user and user, and between designer and user …
this communication is embedded in every kind of artifact.”
(Adler and Winograd, 1992, pg. 7)

Nielsen’s Definition of Usability
Usability is a quality attribute that assesses how easy user interfaces are to use. It includes 5 main components:
Learnability : How easy is it for users to accomplish basic tasks the first time?
Efficiency : Once users have learned the design, how quickly can they perform tasks?
Memorability : When users return to the design after a period of not using it, how easily can they reestablish proficiency?
Errors : How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
Satisfaction : How pleasant is it to use the design?
Jakob Nielsen, source: http://www.useit.com/alertbox/20030825.html

Forms of Usability Testing
(Nielsen, 1992)
1) Testing a close-to-finished interface to check whether usability goals have been achieved
2) Formative evaluation of a system still being designed to see which aspects of the interface work or not

When to conduct Usability Testing?
During the DESIGN phase through:
low fidelity prototype testing
high fidelity prototype testing
heuristic evaluation
During the Development phase
formative evaluation

Heuristic Evaluation
According to Nielsen (1992), we can conduct simple evaluations with 9 usability heuristics (guidelines):
Use simple and natural dialogue
Speak the user’s language
Minimize user memory load
Be consistent
Provide feedback
Provide clearly marked exits
Provide shortcuts
Provide good error messages
Prevent errors

3 Main Components of Testing
Get hold of some representative users ,
Ask the users to perform representative tasks with the design.
Observe what the users do, where they succeed, and where they have difficulties
with the user interface.
“ Listening to what people say is misleading:
you have to watch what they actually do.”
(Image source:http://www.infodesign.com.au/usabilityresources/evaluation/usabilitytesting.asp)

Usability Testing Plan:
Purpose
Why are you conducting the tests?
Problem Statement/Test Objectives
What usability objectives are you testing?
User Profile
Who are your users and their defining characteristics?

Usability Testing Plan
Methods
Details how you will run the test
Task List
List of the tasks to be completed, projected times for completion, required state of system to test tasks
Test Environment/Equipment
List what you need to conduct the test

Setting Usability Objectives
Created during user/task analysis
Must be measurable
Should indicate:
Type of user
Task to be performed
Specific performance criteria

Selecting Test Participants
Define the user groups you are interested in (can segment by age, gender, etc.)
Target 3-5 test participants from each user group
Best if users come from the real user population rather than internally

Methods and Testing Scenarios
The “Think Aloud”
Card Sorts:
Ask for user input on the information architecture or taxonomies
Write topics or categories on cards and ask people to sort them into related concepts or groups

Methods and Scenarios
Questionnaires (with Likert type scales)
Pretests for user’s prior knowledge and skill levels
Usability Lab testing : where they clicked, what they clicked, how long did it take?
Hallway testing : conduct testing with internal participants
Mobile testing : testing participants in their own work contexts
http://www.nngroup.com/reports/prototyping/video_stills.html

New Usability Scenarios
Emerging technologies present new challenges to usability testing,
Technologies are moving beyond traditional office-based personal computer applications.

Emerging Technologies
Characteristics:
Rapidly changing
Technology is increasingly embedded into environment (ubiquitous computing)
Adapted to many more out-of-office contexts
There is more integration among devices (e.g. wireless keyboards, wireless headset, etc.)
More global “market” for products

New Usability Testing?
More emphasis on context of use in testing
Focus on new terms such as “consumer experience” rather than merely “ease of use”
More mobile, ad-hoc, observation based?

Usability

by patty mouzak

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