Human Computer Interaction Flashcards
1
Q
Fundamentally what is HCI?
A
- study, planning and design of interaction between people and computers
- how interactions evolve as people evolve
- community of communities (multidisciplinary)
- bigger than CS itself
- manages innovation to ensure human values and priorities are advanced and not diminished through new tech
2
Q
How does HCI link with cognitive science?
A
- HCI is one of first examples of cognitive engineering
- cognitive science presented people, concepts, skills and a vision for addressing HCI needs through merge of sci and engineering
3
Q
How does HCI link with usability and accessibility?
A
- Usability is open ended concept and can never be reduced to a fixed checklist
- usability is the original focus of HCI
- easy to learn, easy to use
- usability evolved to now associate with qualities such as fun, wellbeing, collective efficient and many more
- design of interfaces that allow people to do work without frustration
- understanding of what people are comfortable with
- systems need to be available to people regardless of disability circumstance, background etc
4
Q
What is conceptual framework?
A
Designers model (model of how system SHOULD work) -> System image (how the system ACTUALLY works as portrayed through interface, manuals etc) -> user model (how the user understands the system) -does the user model match the design model?
5
Q
What is social computing?
A
- computing used to communication, computer is not used to communicate it is used to host the communication platform
- Social media = used for communication + news + entertainment, expected user is everyone, no training required
- online shopping - used for shopping, used by people who may be disabled and cant go shopping or who live far away from shops, or ease of use
6
Q
What is the messy desk metaphor?
A
- files and folders displayed as icons that could be scattered around the display surface
- eventually replaced with search due to clutter
7
Q
How has HCI changed over the years?
A
- moving from expert systems to widely available tech
- closing gap between designer and user
- everyone in the world became a potential comp user in the early 80’s, not just IT profs and hobbyists
- pervasive in daily lives, necessary to participate in society
- way forward for computing entailed understanding and better empowering users
8
Q
3 ways HCI has moved beyond the traditional desktop over time?
A
- social computing
- search feature
- continual diversification in ecology of computing devices
9
Q
What challenges are emerging as HCI develops?
A
-who needs to use the device/software and what are the consequences if they cant?
10
Q
What are some developments in HCI?
A
- increasingly sophisticated documentation considering human theories and testing
- software engineering began focusing on non-fundamental requirements, including usability and maintainability and empirical dev processes
- development in computer graphics began to recognise that interactive systems were the key to progressing
11
Q
How did human abilities/features influence the development of HCI?
A
- need to design equipment and devices that fit the human body and cognitive abilities (pioneered by NASA and IBM)
- need to optimise human well-being and performance
- need to consider humans cognitive limitations (attention, memory, workload)
12
Q
Why is user experience important?
A
- user needs to be put at centre of everything
- requirements, prototyping, development and evaluation all need to include user input
- dialogue is key - constant constructive talk between dev and end user
13
Q
What is the task artefact cycle?
A
- simple terms = I have a task, I develop an artefact, this artefact opens new possibilities for new tasks etc etc
- Human activities have needs, preferences and design visions, artefacts are designed in response
- through course of artefact adoption and appropriations, new designs provide new possibilities for action and interaction
- the activities articulate further human needs, preferences and design visions
14
Q
How has HCI developed in a design sense?
A
- used to be a design science or was thought of as pursuing guidance for designers
- HCI research and design were separate contributing areas of professional expertise
- from 90’s it assimilated and eventually spawned a series of design communities
15
Q
What were original HCI theories?
A
-things such as GOMS (goals, operations, methods, selection rules) which were employed to model the cognition and behaviour of individuals interacting with simple displays, keyboards and pointing devices
16
Q
What are more recent HCI theories?
A
- perceptual theories that explain how objects are recognised in a graphical display
- mental model theories appropriated to explain the role of concepts in shaping interactions
- active user theories explain how and why users learn and making sense of interactions
17
Q
What are the 3 eras of theories?
A
- those that view HCI as information processing
- those that view interaction as initiative of agents pursuing projects
- those that view interactions socially and materially embedded in rich contexts
- eras of theories is idealised. People still work on GOMS etc
18
Q
What is perception?
A
-how information is acquired from the environment via the different sense organs and transformed into experiences of objects, events, sounds and taste
19
Q
What is cognition?
A
-how out mind works
-combines action, perception and memory
-deals with our perception, how we encounter the world, how we process information about it and how we store/recall it
Perception -> thinking and analysis -> memory -> action
20
Q
What are the two types of cognition?
A
- experiential and reflective cognition
- experiential = how we act to events around us effortlessly (driving a car)
- reflective = involve mental effort, attention to judgement and decision making (writing a book)
21
Q
What branches of cognition are relevant to HCI?
A
- perception and attention
- memory
- learning
- interdependent, and several may be involved for a given activity
22
Q
What does the brains information processing depend on?
A
- motivation
- arousal
- individual differences
- cultural differences
23
Q
What is attention?
A
- cognitive process of selectively concentrating on one aspect of the environment while ignoring other things
- allocation of processing resources (limited resources, we must chose wisely)
- focus on info thats relevant to the goals we want to achieve
- information has to be presented in correct way, at correct time, with little clutter to focus attention
24
Q
What are some implications of perception?
A
- not perfect
- can be fooled
- when designing we must help users construct the correct interpretation
25
What is active perception?
-we search for meaning, scanning input quickly, look for meaningful patterns ignoring what doesn’t make sense or what cant easily be decoded
receive input -> assimilate it -> construct our understanding (based on experience) -> brain interprets and makes sense of input based on previous input
26
What are assumptions/interpretations?
- fill in missing details
- ambiguity causes us to see things differently
- the way we see the world is entirely dependent on how the brain interprets and constructs meaning
- have huge affect on design as brain can sometimes be overwhelmed
- must not bombarded user, draw their attention to appropriate information at the right times and provide fine grain details only when needed
27
3 types of memory and the classic view of it?
-short, working and long term
-sensory input (attention)-> STM (practice)-> LTM
-LTM affects attention, practice and STM
Working memory transfer from STM -> LTM, it is where current processing takes place, has new info plus old knowledge
28
What things affect memory?
- context - didnt recognise rory as he wasnt in essex
- attention - more attention given to one thing easier it is to remember
- recognition over recall
29
What’s wrong with STM? What can we do to solve this?
- limited capacity
- recall is easy, recognition is harder
- chunking large information into smaller blocks
- familiarity aids info processing
30
What is Gestalt Psychology?
- our brains want to find patterns and lump info together to make sense of the world. Has 4 laws;
- Law of proximity - if things are close to one another we group them
- law of closure - we fill things in to make shapes such as squares and circles
- law of symmetry - elements that are symmetrical to each other are seen as a group
- law of similarity - link things together that are similar and treat them as a distinct group
31
Features of LTM?
- very large
- associative - time needed to retrieve
- involvement in working memory process
- info can be lost before transfer to LTM thanks to disruption/interruption, anxiety and frustration
32
Recognition vs recall
- people are better at recognising things that have done than recalling things from memory
- eg; GUI vs command line
- recognition tasks provide memory cues that facilitate searching through memory
- sometimes recall can trump recognition; in expert interfaces it might make sense for people to learn how to use an interface dependent on the context
33
Implications of memory in terms of HCI
- when using a computer people are already using a lot of STM
- they are normally doing a task, using the computer as a tool
- shouldn’t have to think of the tool
- reduce memory load, don’t force people to remember info, show menus, maintain consistency, make navigation clear and obvious
34
What is learning?
- acquiring new knowledge, behaviours, skills, values, preferences or understanding
- people learn from experience and consequence
35
What is learning from consequence?
- successful actions will be repeated and vise versa
- depends on the feedback you receive (eg; nice haircut)
- crucial that feedback is timely and specific, the system should be response
- problems occur when feedback is not specific enough
- relatively easy
36
What are alternate ways to learn?
- web-based learning
- VR
- Internet and social media have become cognitive resources that we use in our lives daily to extend our minds
37
When is learning fastest?
When we can
- ID cause and affect
- use prior knowledge
- make connections
- make things obvious
38
How are the senses used in learning?
- meaning of sentence is same weather it is spoken, read or heard
- however ease of these 3 forms depends on the context in which it is portrayed
- need to keep speech based menus short as to not overload
- provide opportunities to make text large on screen
39
What does problem solving require?
- reflective cognition
- what to do? What are the options? What are the consequences?
- discussion, use of artefacts (maps in figuring out how to get around a city) and conscious process (being aware of what one is thinking about)
40
What are affordances?
- perceived properties of the object that suggest how one could use it (eg; chairs are designed so they are easy to sit in)
- can be used in design; website labels, slide to unlock on phones
- user should have to do as little learning as possible, they are interested in the task not the system
- help users but get the timing right; don’t prevent them from reaching their goals, make help optional
41
Types of affordances?
- false affordances = button that turns lights on but doesnt work, push door that says pull
- perceptible affordances = something we think does something and it does ( we think a switch turns on lights and it does)
- hidden affordances = an object has affordances that are not so obvious (looking at a beer bottle you couldnt tell you could open another bottle with it)
- correct rejection = no affordance or misperception that there is one
42
What are conceptual frameworks?
- explain user interaction, inform design and predict user performance
- two types; internal and external
- internal comprises of - mental models, gulfs of execution and evaluation and information processing
- external comprises of - distributed cognition, external cognition and embodied interaction
43
What are mental models?
- internal cognitive framework
- A successful system is one based on a conceptual model that enables users to readily learn that system and use it effectively
- people develop knowledge about a system and try to find out what to do when something does wrong
- more someone learns the more their mental model develops (we have good mental model of how TVs work)
- if people could develop better models of interactive systems, they would be in a better position to know to carry out their tasks effectively
44
What are the Gulfs of execution and evaluation?
- describes gap that exists between the user and the interface
- intended to design interfaces to enable users to cope with them
- Gulf of execution is distance from user to physical system
- gulf of evaluation is distance from physical system to user
- need to bridge the gulf to reduce the cognitive effort required to perform a task
45
What is information processing?
-info is thought to enter and exit the mind through a series of ordered processing stages
-within each stage, various processes (matching and comparing) are assumed to act upon mental representations
-Information processing model provides a basis from which to make predictions about human performance
input or stimuli -> encoding -> comparison -> response selection -> response execution -> output or response
46
What is distributed cognition?
- studies nature of cognitive phenomena across individuals, artefacts and internal and external representations
- focus not on what is happening inside head of individual but across a system of individuals and artefacts
- involves describing a cognitive system, which entails interactions among people, the artefacts they use and the environment they are working in
- how info is represented and re-represented as it moves across individuals and through the array of artefacts that are used during activities
47
What is external cognition?
-concerned with explain the cognitive process involved when we interact with different external representations
-goals are;
> externalising to reduce memory load (writing key dates into diary’s, sticky note reminders etc) helping people to remember when and what they need to do
> computational offloading - using a tool or device in conjunction with external representation to help solve problem (using pen and paper to solve maths problem
> annotations and cognitive tracing - annotating involves modifying external representations (such as crossing things off a list) and cognitive tracing involves externally manipulating items into different orders (such as reshuffling cards in a deck)
48
What is embodied interaction?
- about understanding interaction in terms of practical engagement with the social and physical environment
- provides a framing and organising principle to help researchers uncover issues in the design and use of existing technologies and design of new systems
49
What is usability?
- Refers to the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use
- how well users can learn and use product to achieve their goals
- also considered cost effectiveness and usefulness
50
Why do we focus on usability?
- poor usability will lead to anger, frustration, loss of time on the users end and therefore loss of audience and money on the business end
- no matter how good the information on a site is, if the usability is poor no one will go there
51
What does usability measure?
- Ease of learning - how fast can a new user learn it well enough to do basic tasks
- Efficiency of use - once an experienced user has learned to use the system, how fast can they do tasks
- Memorability - if a user has used the system before can they remember enough to use it effectively the next time or do they have to start over
- error frequency and severity - how often do users make errors, how serious are the errors and how does the user recover from them
- subjective satisfaction - how much does the user enjoy using the system
52
What are usability Heuristics?
- rules of thumb that experts use to ensure their software follows established usability principles
- Applies before software exposed to real people
- two main types; Nielsen (1993) and Norman (1988)
- both are helpful for guiding design process
- A lot of these concepts are based on our understanding of perception, memory and learning
53
What are Norman’s design principles? LONG
| HINT: VAFMCM
Visibility - make functional parts available and easily visible (though all senses)
Affordances / constraints - Properties that things have that invite some actions / discourage action (hazard tape)
Feedback - user should be informed timely and effectively about the outcomes of the actions they are carrying out (% bars when downloading)
Mapping - relationship between controls and things controlled. Poor mapping is evident when a control does not relate with the object it affects, requiring the user to stop and think (kitchen hobs, each dial/button mapped to a specific hob)
Conceptual model - mental simulation of a devices operation (mental model), can be based on mapping’s, affordances and constraints
Metaphors - Make familiar concepts to characterise and explain unfamiliar things/events (Messy desk metaphor).
54
What is a key methodology for carrying out usability?
User centred design
55
What are Nielsen’s 10 usability heuristics? LONG
| HINT: VMUCERFAHH
Visibility of system status - User must be informed of system status. What the system is doing
Match between system and the real world - system needs to speak users lang. Follow real world conventions, making info appear in natural, logical way
User control - users often chose system functions by mistakes and need a clearly marked exit
Consistency and standard - words, situations or actions must mean the same thing. Follow platform conventions and standards
Error prevention - prevent problems and errors. Provide clear messages about the effects of irreversible actions
Recognition over recall - are objects and actions visible? User should not have to remember info from one part of diag box to another
Flexibility and efficiency of use - provide shortcuts for expert users
Aesthetic and minimalist design - diags should not contain irrelevant or rarely needed information, less is more
Help user recognise, diagnose and recover from errors - error messages should be expressed in plain language (no codes) Should indicate problem and suggest a solution
Help and documentation - may be necessary to provide help and documentation. Any such info should be easy to search and has to be focused on the users
56
What is Heuristic evaluation?
- expert evaluators check a site against a predetermined set of usability guidelines, thereby giving your users better experience with product
- finds usability problems and makes them addressable and solvable as part of iterative design process
- evaluators work alone then discuss results to produce list of usability errors to be addressed
- can be used in conjunction with user testing but recommended use is at very beginning of design when product still in paper form
57
How do you carry out a Heuristic evaluation
- record problem
- write down page it was found
- Write down what you were trying to do and what happened
- write down rule it broke
- eg; when entering a password it did not state what characters I couldn’t use. I created one with a special character and it told me this was not allowed. Error prevention
58
What is accessibility?
- The extent to which products, services environment etc are accessible to as many diverse users as possible in as many diverse contexts as possible
- whatever kind of user you are, accessibility becomes relevant when the environment you are in makes it difficult for you to do something
59
What are the three main points from the 2010 equality act?
Legal requirement to....
- Make sure displaced people can have same experience as abled
- fix any physical features that make it difficult for people with disabilities to navigate the space compared to those without
- provide an aid to someone with a disability if without the aid they do not have same access as someone who is abled
60
What are the four categories of disabilities and impairments?
- visual (blindess)
- auditory (deafness)
- motor (paralysis)
- cognitive (memory loss, ADD, autism)
61
What is one big field of study in HCI in terms of accessibility?
- Colour blindness affects 4.5% of worlds population but little is done to help despite the vast amount of research and tech available
- People with the disability see the world very differently that those without (eg; traffic lights, games, MacOS has green red and amber close buttons)
62
What are some Do’s and Dont’s when designing for people with certain disabilities?
Motor:
Do - make large clickable buttons, give form fields space, provide shortcuts
Don’t - demand precision, bunch interactions together, have short time out windows
Low vision:
Do - use good colour contrast and readable fonts, follow a linear layout, use combination of shapes colours and text
Don’t - use low colour contrasts and small font size, use only colour to convey meaning, spread content all over page
Deaf:
Do - write in plain English, use subtitles to provide transcripts for videos, let users ask for interpreters
Don’t - create ambiguity in text, fail to provide subtitles
Autism:
Do - Use simple colours, write in plain English, use simple sentences and bullets
Don’t - use bright contrasting colours, use figures of speech and idioms, create a wall of text
63
What are some other categories that accessibility needs to consider?
Cultural differences:
-groups of people learn idioms (red means danger in the west but in the east its a celebratory colour)
Situational impairments:
- defined as a difficulty accessing a system due to the context or situation one is in, as opposed to a long-term physical or cognitive impact
- includes things like; breaking a bone, being drunk/high, being in a lecture (cant talk to someone on the phone)
- can combat this with; voice control (use Alexa if hands are busy), stylist/conductive gloves if its cold
64
What are two approaches of accessibility?
Accessible design - designing tech to be accessible
Assistive tech - using tech to make the world more accessible
65
What is accessible design? What are the 3 ways it can be achieved?
Design focused on diverse users to maximise the number of potential users who can readily use the system;
- Designing systems that are readily usable by most users without any modification (travellator)
- making systems adaptable to different users (car seat adjustment lever)
- Having standardised interfaces to be compatible with assistive products and tech (hearing induction loops)
66
What are the two steps you need to take when designing accessible systems?
Step 1:
Think about potential user groups - who will use system? Go through list of disabilities and other factors that might hinder access. ID core problems. Don’t make assumptions about user needs based on abilities
Step 2:
Research strategies to design accessibility - existing standards are a good start, look at resources that end user organisations offer, often they provide insight into daily challenges
67
What are standards and guidelines?
- Expert organisations analyse requirements and create lists of features and design guidelines
- Usually very extensive
68
What is ISO 9241-171?
- ISO guidance on software accessibility
- focused on productive software
- extremely technical and formal
69
What is WCAG 2.1?
- Web Content Accessibility Guidelines is a recommendation to make the web more accessible
- Has four main principles; Perceivable, operable, understandable, robust
- the full guidelines are extremely detailed and complex, they take a long time to understand and be confident in
70
What is the first principle of WCAG 2.1?
Perceivable
- information and UI components must be presentable to users in ways they can perceive
- Can’t be invisible to all senses
- Provide alt-text and captions
71
What is the second principle of WCAG 2.1?
Operable
- UI components and navigation must be operable
- interfaces cannot require interaction that a user cannot perform
- Make all functionality available from a keyboard/dont use content that could cause seizures
72
What is the third principle of WCAG 2.1?
Understandable
- information and operation of UI must be understandable
- content or operation cannot be beyond our understanding
- make text and content appear in readable, predictable ways
73
What is the fourth principle of WCAG 2.1?
Robust
- Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive tech
- as tech evolves the content should remain accessible
- maximise compatibility with current and future user tools
74
What are the 3 purposes of alt-text?
1) Read by screen readers in place of images, allowing the content and function of the image to be accessible to those with visual or certain cognitive disabilities
2) places instead of images if image did not load
3) Provides a semantic meaning and description to images which can be read by search engines or be used to later determine the content of the image from page context alone
75
What is the main rule of alt-text?
| What should alt text be?
Rule: If a non-text component conveys content or function, it needs a text substitute
Alt text should;
-be accurate, be succinct, not be redundant, not use phrases “image of...” or “graphics of...”
76
What is the best practice when designing accessible systems? What is the drawback of this and how can this be tackled?
- include user involvement in design process
- provides unique perspective, avoids reliance on assumptions, cannot be reflected by standard documents and allows you to focus on abilities
- approach does take time and creates additional cost
- Can use WAVE (web accessibility evaluation tool) to judge accessibility of a website
77
How can we cater for accessibility in games?
- have re-mappable buttons
- have no button mashing
- no precision
- sensitivity controls
- colour blind options
- easy to read subtitles
- ambient noise
- all audio cues are accompanied by visual ones
78
What is Assistive tech?
- Any item, piece of equipment, or product system, whether acquired commercially or off the shelf, modified or customised, that is used to increase, maintain, or improve the functional capabilities of a person with a disability of impairment
- wheelchairs, prosthetic limbs etc
- many specialised built for purpose systems such as Braille displays that remove need for screen readers and Stephan Hawking’s machine
79
What is user centred design?
- users involved throughout the whole iterative development process
- design is driven and refined by user centred evaluations
- addresses the whole user experience
80
What is the user-centred design cycle?
Requirements -> design -> implement -> evaluate ->
- cyclic process that starts with requirements establishment, leads over to the design and implementation of solutions which are then evaluated
- after evaluation, either exit, or enter new iteration in which requirements are adapted and design and implemented are updated
- system evolves throughout development
81
What is experience centred design?
- deals with the specific experience users have with the product they use; concept rather than a process
- commitment to dialogue with users and communities of interest
- at each stage of the process there are different methodologies that have been found useful for informing the design
- lots of overlap - use the most appropriate methodology to find out the information you need to improve your design at each stage of the process
82
What happens in the requirements stage of the user centred design cycle?
```
-various methods for requirements elicitation (gathering)
Ethnography
Probes
Diary studies
Interviews
Card sorting tasks
Drama/role play
```
83
What happens in the design stage of the user centred design cycle
3 main approaches
- personas
- scenarios
- paper prototyping
84
What happens in the implementation stage of the user centred design cycle
- software engineering methods
| - tools, languages
85
What happens in the evaluation stage of the user centred design cycle
```
Early stages;
-paper and experience prototyping
Later stages;
-working prototype
-diary study
-Analysis of data log files
```
86
What are the pros of user centred design?
- invites participants to creatively express something about themselves, their values, their relationships and the ways they make sense of their experience
- leads you to design useful, interesting, successful tech
- best way to avoid costly errors in development process
87
Difference between functional and non functional requirements?
- Go hand in hand; define system and expectation
- functional are what the product should do
- non functional are how the product should act; describes a product or system characteristic with respect to performance
- we will never know in advance how functional requirements will be met, we must honestly, openly try to understand them
- revisit throughout development process, reassess, ensure nothing went wrong along the way
- understand that users may have different takes on requirements, show behaviours that were not anticipated
88
What are some points to consider when analysing requirements?
- ID what is important to the stakeholders
- involve the stakeholder
- pre prepared; use props, examples, prototypes to support discussion
89
What is requirements elicitation?
-practice of researching and discovering the requirements of a system from users, customers and other stakeholders
90
What is the point in requirements elicitation?
- to catch aspects regarding the experience of people interacting with environment
- to define problems, opportunity and challenges
- understand impact of future tech in everyday life
- help explore the constraints of individuals, interaction with environment, services, artefacts and tech
- catch emotional aspects of interaction in our experiences
- investigates collaborative, individual and emerging behaviour
91
4 main ways requirements elicitation is conducted?
- Ethnography
- Focus groups
- Interviews
- Task analysis
92
What is ethnography?
- direct observations of how people live, work etc
- good to observe people in natural environment without interfering with their activities but no insights into personal opinion and ideas
- everything is viewed as strange
- ID people and situations, gaining access, consent and trust
- watching, listening and experiencing
93
What are focus groups?
- discussing ideas with target audience to elicit their feedback on develops/designers thoughts - not just observing but also interacting
- designer has a plan, they have rough idea of what they want to discuss, they produce materials and props, some guidance on discussion, they record participant responses
- can’t be used for evaluation or usability of a system
- saves money and time but is hard to manage
94
What is a structured interview?
- interviewer asks pre determined questions, like a questionnaire
- everyone asked same questions
- closed questions requiring an answer from a pre-determined set
- only good if goals are well understood
95
What are unstructured interviews?
- exploratory conversations around a topic
- questions are open
- still need a plan
- results in rich, unstructured data
96
What is a semi-structured interview?
- use both open and closed questions
- basic scripts so that the same topics are covered
- begin with pre-planned questions then move on
- dont lead people to conclusions
97
What is task analysis?
- used mainly to investigate an existing situation
- what are people trying to achieve, why are they, how are they going to do it?
- many approaches Ashcroft as a Hierarchical Task analysis
98
What is a Hierarchical Task analysis?
- breaking down task into subtasks and subsubtasks and so on
- focuses on physical and observable actions, and includes looking at actions not related to software or an interaction device
- start with user goal which is examined and the main tasks for achieving it are ID
99
What are the 3 approaches for design?
- personas
- scenarios
- task analysis
100
What is participatory design?
- involvement of end users in the development process not just in the testing phase but as actual designers
- allows you to gain new insights into the users perspectives
- may have insights you do not have or are impossible to imagine
- can work directly with your audience to adapt your project to their needs
- are all the questions appropriate? What if you’re working with vulnerable audiences? Takes time and costs money
101
What are personas?
- precise description of a user and what they want to accomplish
- alternative to directly involving end-users in design
- fictional characters created by designers to represent larger audiences
- still requires insights into needs and wishes of target audience
- can be based on literature, own experiences, group discussion or observations
- include; hard facts about a person, strengths and weaknesses, try to create a full image - hobbies, interests etc
- dont focus too much on software you are trying to design
102
What is scenario-based design?
- narrative descriptions of envisioned usage episodes are employed in a variety of ways to guide development of the system that will enable users experiences
- informal story, simple, natural, personal, not generalisable
- helps understand situations and actions required by the users
- need to include; setting or situation sate, one or more actors with personal motivations, knowledge and capabilities, various tools and objects the actors encounter and manipulate, a sequence of actions and events that lead to an outcome
- persona defines who the story is about, scenarios define when, where and how the story of the persona takes place
103
What are pragmatic and hedonic qualities and societal values?
Pragmatic - speed, efficiency, organisation and usability
Hedonic - appeal to a persons desire of pleasure, fun, original, interesting, engaging and cool
Societal values - privacy, community, family, equality, autonomy, gender roles etc
104
What is a prototype?
- any representation of a design regardless of medium
- an installation of a design hypothesis
- a means to communicate ideas and intent
- a vehicle for evaluating design ideas
- multiple audiences for prototypes - intended users, design teams and supporting organisations
- multiple prototypes yield higher quality feedback than just a few
105
What do prototypes focus on?
- functionality
- visual design
- low-fi vs hi-fi
- Games
- need to know what results you are looking for, what question do you want to answer through the prototypes
106
Why do we prototype?
Help to better understand;
-implications of design decisions
-Existing and missing functionality of a system
-how end users interact with the system
Allows you to continually evaluate project success and therefore save time and money
107
What is prototyping in computer science?
- Has a role in software engineering; usually prototypes are early versions of software
- horizontal vs vertical prototypes; include all features in low-fi or creating hi-fi prototypes of certain aspects
- supports requirements spec
- se user goals as formal use cases
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What approaches are taken in computer science prototyping
- Agile development
- Rapid development cycles that always lead to functional system prototype
- low-fi approach to prototyping
- shifts perspective from functionality to experience
- often applied in games industry because of focus on fun
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How does prototyping relate to HCI?
- interested in how people interact with computers
- not just about functionality of system but the entire experience of using it; usability and accessibility, emotional responses = do people like interaction
- Hi-fi and low-fi are the two approaches used
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What is Low-fi prototyping?
- Focus on user scenarios and goals
- produced quickly and cheaply; used early in dev cycle, requires only basic skill
- dont give many insights into system functionality in action - focuses on UI, interaction sequences etc
- eg; sketching and storyboarding
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What are some low-fi techniques?
Sketching
-drawing out different screens and scenarios on paper, screenshot of system but also user interacting with system
-extends beyond mere system prototyping
Paper
-using paper and pen to create system prototypes
-can be basis for emulating System functionality
-allows for rapid (but limited) prototyping
Story boarding
-like sketching but more formalised
-tells entire story of user interacting with a system
-accessible for other stakeholders without extensive explanations
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What are hi-fi prototypes?
- Meant to look like the finished product
- detailed, real and visual
- Often used for GUI’s
- users cannot easily describe in words the appearances they want and how they can interact with the system, but they can recognise what is acceptable and usable
- developed for mass market, get feedback from potential customers
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What is Wizard of Oz prototyping?
- An experimenter (the wizard), in a lab setting, simulates the behaviour of a theoretical intelligent computer application (often by going into another room and intercepting all communications between participant and system
- Assumes you have a software prototype - user interacts with software and wizard simulates response
- useful for lab studies when field testing would be difficult/expensive/ethical issues
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Benefits and challenges of W Of OZ?
- don’t need to waste your or anyone else’s time implementing a system that turns out to have all the wrong features
- you can test concepts without implementing anything
- can test a variety of them without needing resources
- can test certain features
- faking it well
- need to create a realistic experience
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Benefits of prototyping?
- help designers think from users perspective
- what is potential impact on user?
- what is emotional state when interacting with software?
- may seem a very simple approach, but can bring useful insights without working with users
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What is digital prototyping?
- Storyboarding software
- wireframe tools
- PowerPoint
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What is DECIDE?
-framework about the design and development of a system
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What does the D in DECIDE stand for?
- determine the goals
- what are the high level goals of the evaluation
- who wants it and why
- goals could vary; check user requirements are met, check for consistency or improve usability of existing product
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What does the E in DECIDE stand for?
-Explore the questions
-questions to help guide the evaluation
-Goals of finding out why some customers prefer to purchase paper airline tickets rather than e-tickets can be broken down into sub questions;
> what are the customers attitudes to e tickets?
> are they concerned about security?
> is the interface for buying them poor?
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What does the C in DECIDE stand for?
- Chose evaluation approach and method
- evolution method influences how data is collected, analysed and presented
- observation and interviews, users in natural settings
- not controlled tests
- produces qualitative data
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What does the I in DECIDE stand for?
- ID practical issues
| - for example how to; select users, find evaluators, select equipment, stay on budget and schedule
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What does the second D in DECIDE stand for?
-Decide about ethical issues
-develop an informed consent form
-participants have right to:
> know the goals of the study
> know what will happen to the findings
> privacy of personal info
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What does the second E in DECIDE stand for?
- Evaluate interpret and present data
- methods used influence how data is evaluated, interpreted and presented
Following needs to be considered:
- Reliability
- validity
- Biases
- Scope = can findings be generalised
- ecological validity = is the environment influencing findings
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What is inspection?
| What are Heuristic evaluations?
- Invites experts to comment on system
- mainly applied in usability engineering
- Good at beginning of development
-uses existing heuristics to inspect systems; asks whether system complies with guidelines
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Pros and cons of inspection?
+Quick
+cheap
+easily repeatable
+easily translates into action items for developers
+Likely to ID biggest usability issues that need to be addressed by designers
- Availability and affordability of experts
- correct interpretation of guidelines
- No insights into how actual users interact with the system - could miss important points
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What is testing?
- involves users
- based on gathering user feedback to ID areas for improvement, validate features of gain insights into how system affects them
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How do we recruit users for testing?
- Could be done with screening; they were not involved in the design and dev of the site or product, represent a huge target audience
- Need to know; how many people who need, when and where test is, how long it will take, what you will provide
- Nielsen outlines number of participants needed based on several case studies; for example card sorting needs 15 people but usability test only 5
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Pros and cons of testing?
+Actual feedback from real people
+insights into how people interact with system in lab or field
+scientific approach to evaluations in HCI
+real world testing = high validity
- requires planning which takes time
- recruiting the right sample can be hard
- additional knowledge necessary to analyse and interpret results - results need to be made actionable
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Inspection Vs testing
-inspection relies on experts and heuristics, testing relies on users
-Which one to use depends on context;
>Low-fi vs Hi-fi system status
> what questions you want to answer?
>how much time you have?
-methods can be complimentary, try inspections before testing
-inspections are usually quicker, testing can provide deeper insights and both can complement each other
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What are lab tests?
- any kind of controlled environment that can create to test your system (room on campus, coffee shop etc)
- controlled but not realistic environment
```
+controlled environment
+max surveillance potential
-validity - artificial environment
-longitudinal evaluations tiresome for user
-requires testing facilities
```
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What are field tests?
- natural habitat of your users
- realistic but not always easy to research environment
+natural habitat - ecological validity
+easier longitudinal deployment
-user feedback may be harder to obtain
-methodologically challenging
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Lab vs field tests
- depends on question you are trying to answer
- user groups your working with
- type of system your developing
- availability of resources
- a utopia is a combination of both resources to get max amount of insight
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What is quantitative data?
- interested in quantity of phenomena and asks about the experience of many
- works with bigger user groups
- challenge is choosing the right instruments and getting data analysis right
- benefit would be getting a thorough understanding of bigger picture
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How can user interaction with a system be quantified?
With different measures;
- questionnaires
- observations
- metrics
- more complex approaches such as biometrics
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What are questionnaires?
-instrument to gather structured feedback from people; usually consists of a range of items (questions) and is focussed on a specific topic
Can be;
-binary (yes/no)
-categorical
-Ranking
-Scalar: Semantic differential (eg; “Using the interface was; chose an option 1-5 with 1 being easy and 5 being hard”)
-Scalar: Likert (strongly agree/disagree)
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What is observation?
- observing how a person interacts with system (eg; facial or verbal comments)
- challenge is knowing how to record data appropriately
- Step 1; define quantifiable observations
- Step 2; Ensure observations are consistent across many participants
- Need to decide how and when to make observations; either while user interacting with system or record interaction and analyse the recording
- Option 1 takes less time but requires development of coding scheme in advance, option 2 allows you to explore recordings first
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What are metrics?
-Offer objective insights into how user interacted with system;
>Time taken to complete tasks
>Number of tasks completed within a set time
>Number of errors made in completing a task
- easy to present and analyse but recording requires prep
- do not provide enough insights if they are sole measure - can only tell you what happened not why
- Good way of backing up questionnaire results and observations - especially if findings from questionnaires and observations contradict
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What are the modern day ethical principles?
- informed and voluntary consent
- favourable risk-benefit ratio
- confidently and data protection
- independent review process for research
- justice and inclusiveness
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When do ethical principles apply?
-When you are conducting research; an undertaking to extend knowledge through discipline inquiry or systematic investigation
-activities that are not research would not be subject to research ethics or an ethical review
-Only apply to studies that involve one or more of;
>Human participants in active capacity
>the recording of personal data
>collection of biological tissue
>animal participants
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What is informed and voluntary consent?
- participant is given all the info needed to decide on whether to take part in the research
- researchers ID, Purpose, method and data use
- short simple and clear - not long T&C’s
- participants chose to take part willingly and have the right to withdraw at any time without any consequences at any time - even after study
- coercion to force people to take part in study through physical or psychological methods is not allowed
- assume everyone can make decisions unless there is proof that they cannot
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What are some exceptions to gaining explicit consent?
- impractical
- impossible
- covert research = only allowed when the study is of scientific significance or overt research not possible; should still tell participant afterwards and allow them to withdraw
- exceptions should be made with care, if gaining consent is impossible it does not mean the study is ethical without consent
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What favourable risk-benefit ratio?
-Aim should be beneficial and follow on from prior scientific knowledge
-minimising risk depends on the likelihood of harm and the impact of harm if it does happen
-unethical if;
>does not have solid scientific foundation
>it is not run by a trained by a trained competent professional
>does not follow well-defined procedures to ensure success
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What types of risk are there?
- physical
- social
- emotional
- financial
- professional
- vulnerable groups should be given extra care, researchers should be cleared by DBS
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What is confidentiality and data protection?
- participants should be guaranteed confidentiality, particularly in studies involving sensitive or stigmatised topics
- personal data should be kept private and safe
- GDPR states personal data is any info relating to an id or identifiable natural person, ID either directly (ID from info) or indirectly (ID from info combined with other info)
- studies in Germany show you can find ID of someone by simply having their browser history
- difficult to enforce and leaves vulnerabilities undiscovered
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What are some examples of sensitive personal data?
- racial or ethical origin
- political opinions
- trade union activities
- sex life
- mental and physical health
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How do we ensure data privacy?
- only keep info if needed and for as long as needed (data retention)
- use numeric indexes to link ID with non-ID data
- don’t fully anonymise data as participants still need ability to withdraw
- US privacy laws are weaker then EU ones so storing personal data on cloud services whose servers are in the US would violate GDPR
- only ask for sensitive data if it is vital to research
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What are some exceptions to data privacy?
voluntary - participants may want to be ID; may partly waiver their confidentiality
Statutory - legally required to report evidence of crime/intent to commit crime and evidence of risk of vulnerable persons
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What is independent review process?
- decision on whether research is ethical or not should NOT be left to the researcher to decide
- REC, research ethics committee, is required in any institution that takes government funding
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What is justice and inclusiveness?
Justice = benefits and burdens of the research must be distributed
-if your study will benefit a certain portion of the population this should be reflected in the participants you use
Inclusiveness = no group of people should be, without good reason, excluded from research activity that affects them
-need to have a good reason to eclipse someone from participating in your study
-eg; not allowing person who cannot read from taking part in a study where no reading is needed violates this principle
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What is the key principle of being and ethical researcher?
Being an ethical researcher is an active process and requires constant reflection and awareness of the direct and indirect consequences of your research
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What is the design-data cycle?
System hypothesis -> collect data -> visualise data -> describe data -> analyse data with respect to hypothesis which may result in another hypothesis and so on
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What are the 3 types of data?
Categorical - data that’s values can be sorted according to a category, and each value is chosen from a set of non-overlapping categories (eg; either dead or not)
Ordinal - values can be ranked naturally or have a rating scale attached, number don’t always imply rank, could for a code for a category, there is order but not set distance between items (eg; rank 1 and 2 may be closer than 2 and 3)
Continuous - values may take on any value within a finite or infinite intervals, can be counted and measured (eg; height)
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What is a SUS questionnaire
- Quick and dirty way to measure usability
- 10 questions with 5 response options ranging from strongly agree to strongly disagree
- very easy to use and great for small sample sizes
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What is data visualisation?
- distribution of data can give insights, and will tell you which math operations and stat tests you can apply 0 uniform, bimodal, skewed etc
- Avg = single value that describers entire distribution
- Mode = works well on all types of data
- median = ordinal data and up, splits dataset at 50%
- mean = continuous data, susceptible to extreme values
- spread = allows you to give additional information about the distribution you are trying to characterise
- degrees of freedom are the number of observations that are free to vary
- range = ordinal data
- variance and SD = continuous
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What are correlation and the correlation coefficient?
- correlation = the extent to which there is a linear relationship between two sets of data, an association
- r value = correlation coefficient, close to +1 or -1 means the closer they are related
- just because a strong association exists doesn’t mean that one variable causes the other; could be common third factor affecting relationship or coincidence
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What is goal of data analysis?
- to describe data and explore relationships within it
| - important to chose right description and analysis approaches to accurately represent and interpret results
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What is effect size?
- What is the size difference between my two sets of data
- What impact is this likely to have?
- Simple diff = meanA-MeanB
- Cohen’s D = gives absolute difference between means
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What are confidence intervals?
-range of values we are sure our true values lies in
-format [min, max], contains the mean
Mean +- Z*(S/sqrt(N)) where mean is the mean of the data set, Z is a set value corresponding to what % we are trying to fine (look up in Z table), S is standard deviation and n is number of observations
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What is the null hypothesis?
No real difference between our conditions
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What is the P value?
- Chance of an outcome as extreme as the actual observation
- if P is small enough, then this indicates that the null hypothesis is not true
- chance that through random selection you would get the data drawn by these distributions
- Alpha is the threshold between a significant and non-significant P-value (0.05 in comp sci)
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What is the students T-test?
- Assess whether the means of two sets of data are significantly different
1) Calc descriptive stats (mean, median etc)
2) Calc t-stat
3) look up threshold in t-distribution (0.05) is result significant?
4) service p-value from Z tables
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Parametric vs non parametric tests?
- Aim to use parametric test, unless the assumptions are specifically violated
- parametric give more statistical power
- non parametric are good if you have a small sample size
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What is the man-Whitney U test?
- non-parametric equivalent to the parametric t-test
- test to see whether one dataset mean is significantly different from another
- results in a U stat rather than a T stat
- Both will give you a P value, so you can interpret the data in the same way (try to reject the null hypothesis etc)
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What are some limitations on P values?
-on its own say nothing about the magnitude of the effect
-Lower P value does not imply you have a stronger effect than a higher P value even if both values are below the 0.05
threshold
-not reliable indicators of replicability; you will see a wide range of p values if you repeat experiment multiple times
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What is regression analysis?
- Extent to which there is a linear relationship between two sets of data
- R value
- R^2 Value is the % of related fairness (goodness of fit)
- can test significance of the line slope (null hypothesis = slope of zero)
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What is the goal of statistical analysis?
- to describe data and explore relationships within it
- important to chose the right description and analysis approaches to accurately represent and interpret results
- in this way you can best use your result with respect to the initial experiment/hypotheses and to the system you were evaluating, so you can better improve your system
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Quantitive vs qualitative data?
```
Quantitive = quantity of phemona and asks about the experience of many (statistical data analysis with mean etc)
Qualitative = understand the quality of phenomena rather than simply their quantity. Less participants but more in-depth data gathering and analysis. Understanding why and how decisions are made. Focus groups, interviews etc
```
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When is qualitative research good?
Useful when data you are interested in is;
- not easily observable, cant be easily or meaningfully reduced to numbers (feelings, values abstract concepts etc)
- cant be experimentally manipulated (ethics)
- Complexity (more variables than you can measure, known variables interact in unpredictable ways
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Some examples of qualitative data?
- quotes from participants
- in-depth descriptions of observed behaviour
- images
- narrative
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Why use qualitative methods in CS?
- to determine what might be important to measure, why measured results are as they are, or if the subject of study cannot be measured easily
- to understand not only what happened, or what people are responding to, but why
- to understand and explore what a technology or practice means to people
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What is the qualitative process?
- data collection = interviews observations
| - data analysis = coding, grounded theory, affinity diagram
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What is ethnography?
- direct observations of how people actually live, work etc.
- ID people and situations, gaining access, consent and trust
- take notes, searching for patterns and uniqueness
- four key principles; context (go to where the activity is), partnership (talk about activity), interpretations (find/make meaning, investigate (look for supplies)
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What type of data comes out of ethnography?
- handwritten notes
- drawing/sketches
- audio recordings
- video recordings
- all time consuming but more data the better
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In terms of ethnography what are field notes?
- note rough times down side of the page, numbering each line
- next to each line, write your descriptions, describe locations, people in setting etc
- write down what everyone did and said
- write down your questions and their responses
- note down your interpretations
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Pros and cons of ethnography
- good for design and evaluation
- often gives direct insights
- combined with other sources of info such as interviews
- time consuming
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What is the structure of an interview?
Intro - define setting and role
Warm up - start introing subject
General issues - focus on general expectations, assumption and experiences
Deep focus - intro the product/idea and get attention to some details
Retrospective - going back to general issues (any change?)
Wrap up - make it clear that it is over
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Some rules to follow in an interview?
- ask Indirect questions only, let the users true feelings come out, dont let them please you
- be as unbiased as possible
- keep each question focused on one topic
- ask open ended and non-judgemental questions
- avoid binary yes/no questions
- dont ask leading questions that may suggest one of the answers is wrong
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Pros and cons of interviews?
- interactive, researcher can drill deeper
- time efficient
- good interviewing is not easy
- what they say vs what they do
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What are focus groups?
- series of tightly moderated group discussions
- discussing with target audience to elicit their feedback on developers/designers thought; not just observing but also interacting
- steering discussion and probing but letter the users explain their experience
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What things need to be considered when creating focus groups?
- Participants = chose the proper people, based on your target audience and the topic you want to discuss. Avoid experts, dominate people and people who know each other
- topic = choose the proper topic for the specific group of participants
- scope = determine in advance the number of groups and the purpose of each one of them. About 4 different groups is optimal, dont trust 1
- discussion guide = prepare it carefully for each group, make non-directed and open ended questions, focus on the specific without making it personal
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What is the difference between moderator and observers?
- moderator = neutral, non-judgemental, respectful and in control
- observers = observe; better to video each group
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What does analysing a focus group consist of? How are focus groups bad?
- immediate debriefing
- use all material
- extract trends
- compare different opinion
- useless for usability info
- statistically irrelevant
- can real a thing but not quantify it
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What is thematic analysis?
- methods that result in lots of unstructured and messy data
- how do we draw data together?
- thematic analysis helps this and themes are always emergent from data
- have to read and understand the data then break it down into chunks, then code it
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In terms of thematic analysis what is reading and chunking?
-each block should be a seperate idea
-read multiple times
-aren’t interested in the specific words but rather the message conveyed
(What’s the person telling us)
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What is coding? (In terms of thematic analysis)
- many ways to do it, allows for recording of data and presentation of ideas in a more clear and informative way
- done independently by 2 researchers and results are compared for agreement
- in viva codes = wording participants use in interview
- constructed codes = coded data from in viva codes, created by researcher, academic terms
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In terms of thematic analysis how do we ID reoccurring themes?
- high level analysis intending to get a broad picture
- read the text, noting on the transcript any patterns or themes that emerge (behaviour, places etc)
- ID themes and patterns from a sample of data, then try and apply those to the rest
- at the end should have list of most important themes from your data, but also you will have easy to find raw data to back up your point
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What are memos?
- way of analysing a response to a question (the respondents choice of wording etc)
- keep separate from data
- stop coding when an idea for memo occurs, so as to not lose the thoughts
- can be brought to you literally by forcing it
- when a lot of memos on different code appear similar, compare the code for any differences that may have been missed. If the codes still seem the same, collapse the two codes into one
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In terms of thematic analysis what is categorising data?
- much more detailed and technical analysis
- often there are categories in existence in advance
- appropriate when you want the data in the form of structured categories
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In terms of thematic analysis what is reporting?
- what you report depends on analysis done
- generally, use evidence from the text to support your analysis
- thematic analysis = state a theme, an explanation of that theme, a quote/quotes illustrating that theme
