Complete List of Terms and Definitions for HCI Usability - User Research
affordance are the ways things tell you what they do...
what do things look like or feel like they do? how do you design affordances into things? how do you make it feel like it does what it actually does?
what happens when i do this.. or this... or how about that? is it what i expected?
What is the Star view or design?
a.k.a. Hartson & Hix made it up
|Name 3 kinds of approaches to user centered design?||
USABILITY is ____?_____
HINT: THERE ARE 5.
EFFICIENCY OF USE: high speed of user task performance
LEARNABILITY: ease of learning
MEMORABILITY:user retention over times
ERRORS:low user error rate and easy recovery form error, with good error message design
SATISFACTION (USER'S): subjective users satisfaction
|functional requirements?||what the thing actually has to do, accomplish, its real purpose for existing, the lead reason|
Catergories of user
Expertise in using the system
Extent of use of the system
–New vs. Experienced Users
–Knowledgeable vs. ignorant
Experience with computers
–New vs. Experienced Users
|Summative Evaluation is _____.||
Done on completion of stages
supposedly these are "Design Strategies"
i doubt it
Top down design
Bottom up design
Analysis of task and knowledge of user
Educated common sense
Knowledge of human characteristics
Awareness of own ignorance and skills of others
Attention to detail
Understanding the payoff of good HCI.
|constraints of input / output devices?||
|Things we can measure environmentally speaking...||Presence and availability of information ...colleagues, manuals, on-line helpSpeed of response, size of screen, ergonomic factors, compliance with guidelines|
|what is UCD?||
user centered design.
UCD focuses on involving users at every stage in the development and evaluation of alternative designs.
|Functional requirements are __________.|
|what is input?||
What is input?
–Choice of limb, type of control, method of operation, position of control, label, feedback of operation
What are input devices?
–Give instructions to computer
–Select best one for the job
–Consider underlying issues
|Thinking Aloud Protocol||
What does the subject notice?
What is the subject thinking now?
Goal (what is subject trying to do)?
Plan (how is he/she trying to do it)?
Is this achieved?
Suggestion made by the subject
Activites needed for user centered design?
hint: there are 4, and you've only heard them a million times
Identifying needs and establishing requirements
Developing alternative designs
PROTOTYPING - Building interactive versions of the designs
Evaluating the designs
|Jacob Nielsen's Summary of Usability Inspection Methods:||
Heuristic evaluation is the most informal method and involves having usability specialists judge whether each dialogue element follows established usability principles (the "heuristics").
Heuristic estimation is a variant in which the inspectors are asked to estimate the relative usability of two (or more) designs in quantitative terms (typically expected user performance).
Cognitive walkthrough uses a more explicitly detailed procedure to simulate a user's problem-solving process at each step through the dialogue, checking if the simulated user's goals and memory content can be assumed to lead to the next correct action.
Pluralistic walkthrough uses group meetings where users, developers, and human factors people step through a scenario, discussing each dialogue element.
Feature inspection lists sequences of features used to accomplish typical tasks, checks for long sequences, cumbersome steps, steps that would not be natural for users to try, and steps that require extensive knowledge/experience in order to assess a proposed feature set.
Consistency inspection has designers who represent multiple other projects inspect an interface to see whether it does things in the same way as their own designs.
Standards inspection has an expert on an interface standard inspect the interface for compliance.
Formal usability inspection combines individual and group inspections in a six-step procedure with strictly defined roles to with elements of both heuristic evaluation and a simplified form of cognitive walkthroughs.
|The Usability Engineering process is based on______.||
Collect & synthesise information about users and tasks - understand users
Develop a conceptual design of interface
–User’s mental model?
Test with users
Set usability goals
uPrototype & evaluate
|Model of Usability Measurement:|
designing gooood systems
Define the problem the customer wants solved
Identify tasks the user must perform
Learn user capabilities
Learn hardware & software constraints
Set specific usability targets in behavioural terms
Types of prototypes
Quantifiable Usability Measurements:
The time users take to complete a specific task
The number of tasks that can be completed in a given time
The ratio between successful interactions and errors
The time spent recovering from errors
The number of user errors
The number of features/commands utilised by users
The number of system features the user can remember in a debriefing after the test
The proportion of user statement during the test that were positive versus critical toward the system
The amount of ‘dead time’ during the session
–social and cultural
|The usability lifecycle chronicles the life cycle of usability development and it looks like this...|
|Jacob Nielsen's 10 recommended heuristics for evaluation:||
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 the 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.
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.
|4 main usability engineering principles||
1. FOCUS ON THE USERS
2. INTEGRATED DESIGN
3. USER TESTING
4. ITERATIVE DESIGN
now repeat that 4 times aloud...
seriously... do it now!
|What is the Spiral model of design?|
|Assumptions we make to evaluate_____________.||
–we know what the interface is meant to be doing
–we can measure aspects of its performance
–we can make judgements and assessments on the basis of these measurements
|GOOD DESIGNED SYSTEMS ARE GOOD.||
Sketch out user scenarios
Design and build prototype
Iteratively incorporate changes and test until:
Behavioural targets are met
A critical deadline is met
Install system at customer location
Measure customer reaction and acceptance
|usability requirements?||the touchy feely, how the people are going to work the machine and how it guides them through the process|
NO JUST BAD DESIGN
Inapropriate error messages
Useless error messages
Lack of Control
Un-necessary data entry
Inconspicuous warning messages
Easy to perform dangerous actions
Complex process to be remembered
YOUR DESIGN PHILOSOPHY
Borrowed from film and television
–used to plot film/play simply
–to try out ideas without incurring huge costs
Think of your program design as telling a story … it should have the same elements:
–enjoyable to watch
–easy to understand
Things we can measure
about the user...
Attitudes and values
Knowledge, from questions and performance
Intentions and goals
–keystrokes, commands used, actions done
–time to perform tasks
–learning and retention
Self estimates of performance
Combining Usability Methods:
Pick, Mix and Adapt
–Heuristic Evaluation 1st
–Think Aloud 2nd
–Heuristic Evaluation 1st
–Performance Measurement 2nd
–Follow-up Questionnaire 3rd
These methods find distinct sets of usability problems
|LAWS OF GROUPING||
A Gestalt approach to perceptual organisation
focus on seeing well-organised and meaningful wholes
not isolated and disparate parts
|Formative Evaluation is _____.||
To help change
Goes on throughout development
The ARTILLERY method
of design is based on?
design / redesign = READY
prototyping / implementation = FIRE
evaluation / analysis = AIM
|What is the wheel model?|
hint: its a diagram
the main principles of
good error message design
Show where the error(s) occurred in the form.
Clearly explain what the error is (and how to fix it).
Use color and possibly icons to make the error information stand out.
|Impairments of older people:||
- Physical Impairment / Weakness
- Cogition impairment
A usability (behavioural) goal ...
think of the kind of langauge you would use to word a usability goal
|“The CAL system to teach Standard Grade Mathematics must be capable of being used by schoolchildren aged 14, without reference to manuals and without user intervention. It must enable the children to learn the key points of each lesson within 15 minutes and 80% of the children should enjoy using it.”|
|Why do we evaluate?||
to make the interface better
to ensure that it is usable in real-life settings
adequacy for purpose / meeting standards
–Number of errors users make in an hour?
–<=2 (better than current version/competitor)
Minimum Acceptable Level
–4.5 (usu. equal to current version/competitor)
–>4.5 (less than current version/competitor)
For completely new systems, usability goals are much harder to set
|User Interface Management Systems||
Separates interface code from application code
Facilitate development of interfaces
May contain interface elements and
knowledge of good practice
with a little sugar on it
Memory & Recall
Fatigue & Emotions
Visual, Auditory and Tactile Perceptions
Knowledge of the world
humans are not the same as computers
humans are not the same as other humans
think about it and make it part of your design
4 KEY principles of
1. Early - and continual -FOCUS ON USERS, USER-CENTERED, PARTICIPATORY DESIGN
2. Integrated design RECOGNIZE THAT USABILITY IS IMPORTANT
3. Early - and continual - USER TESTING, ALL THE METHODS
4. Iterative design- DOING IT ALL OVER AND OVER AND OVER
|Designing good interfaces is founded on______.||
Sketch out user scenarios (eg storyboards)
Test (evaluate) scenario with users
Design and build prototype
Test (evaluate) prototype with users
Iteratively incorporate changes and test until:
–Behavioural targets are met OR A critical deadline is met (you run out of time?)
|Another favorite method of annalu's to discuss?||roleplaying and theatre of the opressed, where actors come in a play pre written roles to draw out the discussion|
What is Usability?
Hint: ISO - definition, or the EES definition
Usability is the effectiveness, efficiency and satisfaction with which specified users can achieve specified goals in particular environments
-Effectiveness is the accuracy and completeness with which users achieve specific goals.
-Efficiency is the accuracy and completeness of goals achieved in relation to resources expended.
-Satisfaction is the comfort and acceptability of using the system
|Conducting Usability Tests?||
Select a representative group of users
Decide which usability indicators to test
(e.g. learnability, efficiency)
Decide the measurement criteria
Select a suitable test
Remember to test the software not the user
Collate and analyse data
Feed the results back into the product
|How to collect data?||
Logging Actual Use
The traditional develpoment lifecycle...