1. Chapter 3
Understanding users

2. Outline
What is cognition?
Cognitive frameworks

3. Why do we need to understand users?
Interacting with technology is cognitive
We need to take into account cognitive processes involved and cognitive limitations of users
We can provide knowledge about what users can and cannot be expected to do
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4. Why do we need to understand users?
Identify and explain the nature and causes of problems users encounter
Supply theories, modelling tools, guidance and methods that can lead to the design of better interactive products
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5. What is cognition? (การรับรู้)
What goes on in our heads when we carry out our everyday activities
Cognitive processes: thinking, remembering, learning, daydreaming, decision-making, seeing, reading, writing, and talking

6. Kinds of cognition Norman (1993) 1) Experiential cognition
a state of mind in which we perceive, act, and react to events around us effectively and effortlessly
requires reaching a certain level of expertise and engagement
Examples: driving a car, reading a book

7. Kinds of cognition Norman (1993) 2) Reflective cognition
involves thinking, comparing, and decision-making
leads to new ideas and creativity
Examples: designing, learning, and writing a book

8. Specific kinds of processes
Attention*
Perception and recognition*
Memory*
Learning
Reading, speaking, and listening
Problem-solving, planning, reasoning, decision-making

9. Attention
It is the process of selecting things to concentrate on, at a point in time, from the range of possibilities available
Involves auditory and/or visual senses
ex. Auditory – waiting in the dentist’s waiting room
Visual scanning the football results

10. Attention Whether this process is easy or difficult depends on
1) clear goals
ex. clear goals – finding out World Cup results of your favorite football team
ex. unclear goals – not sure what to eat
2) information is salient in the environment

11. Attention Whether this process is easy or difficult depends on
1) clear goals
2) information is salient in the environment
information presentation: the way information is displayed can also greatly influence how easy or difficult it is to attend to appropriate pieces of information

12. Attention Attention enables us to focus on relevant information But
This means we can’t keep track of all information

13. Attention
Information at the interface should be presented to attract users’ attention, e.g. use color, sound and flashing lights

14. Activity
Tullis (1987) found that the two screens produced quite different results
1st screen - took an average of 5.5 seconds to search
2nd screen - took 3.2 seconds to search
Why, since both displays have the same density of information?
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15. Activity
Spacing
In the 1st screen the information is bunched up together, making it hard to search
In the 2nd screen the characters are grouped into vertical categories of information making it easier
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16. Design implications for attention
Make information salient when it needs attending to
Use several techniques to achieve this
ex. animated graphics, color, underlining, spacing of items
Avoid cluttering the interface with too much information, ex. google.com

17. Perception and recognition
how information is acquired from the environment and transformed into experiences
it is complex, involving other cognitive processes, e.g. memory, attention, and language
it is important to present information in a way that can be readily perceived in the manner intended

18. Activity
Weller (2004) found people took less time to locate items for information that was grouped
using a border (2nd screen) compared with using color contrast (1st screen)
Some argue that too much white space on web pages is detrimental to search
Makes it hard to find information
Do you agree?
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19. Perception and recognition
Information needs to be represented in an appropriate form to facilitate the perception and recognition of its underlying meaning
Example: lip-synch applications

20. Design implications for perception
Information is represented to be perceptible and recognizable across different media
Icons and other graphical representations’ meaning should be obvious to users
Bordering and spacing are effective visual ways of grouping information, making it easier to perceive and locate items

21. Design implications for perception
Sounds should be audible and distinguishable
Speech output should be clear so that users can understand their meaning

22. Design implications for perception
Text should be legible and distinguishable from the background
Tactile feedback should allow users to recognize meaning of various touch sensations

23. Memory
Involves encoding and retrieving (recall) various kinds of knowledge
We can’t remember everything
Filtering process

24. Memory
The more attention paid to something and the more it is processed in terms of thinking about it and comparing it with other knowledge, the more likely it is to be remembered
The context in which the information is encoded
Example: seeing your neighbors on a train instead of in the hallway of your apartment

25. Memory People are better at recognizing than recalling
Example: people are very good at recognizing thousands of pictures even if they have seen them briefly before

26. Memory People are good at remembering visual cues about things
Examples:
color of items
location of objects
marks on objects
People find it more difficult to learn and remember arbitrary material, e.g., birthdays, phone numbers

27. Recognizing easier than recalling
GUIs provide visually-based options vs. command-based systems
Displaying lists of visited URLs

28. Design implications for memory
Don’t overload users’ memories with complicated procedures for carrying out tasks
Design interfaces that promote recognition rather than recall
Provide users with a variety of ways of encoding digital information to help them remember where they have stored them
e.g., categories, color, flagging, time stamping

29. Learning 2 interpretations: 1) how to use a computer-based application
2) using a computer-based application to understand a given topic

30. Learning 1) how to use a computer-based application
Jack Carroll (1990)
Users prefer to ‘learn through doing’
GUIs and direct manipulation interfaces
Support exploratory interaction
Allow users to ‘undo’ their actions

31. Learning Jack Carroll “training-wheels’ approach
Restrict possible functions to the basics for a novice
Extend these as the novice becomes more experienced
Rationale: make initial learning more tractable -> help learner focus on simple operations before moving on to more complex ones

32. Learning
2) using a computer-based application to understand a given topic
Use interactive technologies, e.g. web-based, multimedia, virtual reality
Help users to better understand abstract representations of the materials
Make a connection between abstract representations, e.g. diagrams, text, etc., and concrete representations through interactive technologies

33. Design implications for learning
Design interfaces that encourage exploration
Design interfaces that constrain and guide users to select appropriate actions when initially learning
Dynamically link concrete representations and abstract concepts to facilitate learning of complex materials

34. Reading, speaking, listening
Differences
Written language is permanent (i.e., enables rereading); listening is transient
Reading (i.e. via scanning) can be quicker than speaking or listening
Listening requires less cognitive effort than reading or speaking

35. Reading, speaking, listening
Differences
Written language tends to be grammatical; spoken language is often ungrammatical
People’s ability to use language is markedly different
People with hearing and sight problems are restricted in the way they can process language

36. Design implications for reading, speaking, listening
The length of speech-based menus and instructions should be at a minimum
Accentuate the intonation of artificially generated speech voices
Provide alternatives to make text large on a screen, without affecting the formatting, for people who find it hard to read small text

37. Problem-solving, planning, reasoning, decision-making
All of these processes involve reflective cognition
thinking about what to do, what the options are, and what consequences of actions might be
The extent to which people engage in reflective cognition depends on their level of experience with a domain, application, or skill

38. Design implications
Provide additional information to help users learn more about how to carry out an activity more effectively, e.g. web searching
Use simple and memorable functions for applications supporting rapid decision making and planning on the move

39. Cognitive frameworks
Are conceptual frameworks that explain and predict user behavior based on theories of cognition
Influential ones are:
Mental models
Theory of action
Information processing
External cognition
Distributed cognition

40. Mental models
Users develop an understanding of a system through learning and using it
A user’s mental model
Knowledge of how to interact with a system
How that system works

41. Mental models
Used by people to reason about the system and to figure out what to do when something unexpected happens or when encountering unfamiliar systems
Craik (1943) described mental models as internal constructions of some aspect of the external world, enabling predictions and inferences to be made

42. Mental models
Involves unconscious and conscious processes, where images and analogies are activated
Deep versus shallow models (e.g. how to drive a car and how it works)

43. Everyday reasoning and mental models
You arrive home on a cold winter’s night to a cold house. How do you get the house to warm up as quickly as possible? Set the thermostat to be at its highest or to the desired temperature?
(b) You arrive home starving hungry. You look in the fridge and find all that is left is an uncooked pizza. You have an electric oven. Do you warm it up to 375 degrees first and then put it in (as specified by the instructions) or turn the oven up higher to try to warm it up quicker?
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44. Heating up a room or oven that is thermostat-controlled
Many people have erroneous mental models (Kempton, 1996)
Why?
General valve theory, where ‘more is more’ principle is generalised to different settings (e.g. gas pedal, gas cooker, tap, radio volume)
Thermostats based on model of on-off switch model
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45. Heating up a room or oven that is thermostat-controlled
Same is often true for understanding how interactive devices and computers work:
Poor, often incomplete, easily confusable, based on inappropriate analogies and superstition (Norman, 1983)
e.g. elevators and pedestrian crossings - lot of people hit the button at least twice
Why? Think it will make the lights change faster or ensure the elevator arrives!
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46. Transparency
To help users develop better mental models, the interactive systems could be designed to be more transparent
Transparency involves:
Useful feedback in response to user input
Easy-to-understand and intuitive ways of interacting

47. Transparency Also provide the right kind and level of information
Clear and easy-to-follow instructions
Appropriate online help and tutorials
Context-sensitive guidance for users, set at their level of experience, explaining how to proceed when they are not sure what to do at a given stage of a task

48. Theory of action
Another way to conceptualize user-system interaction is in terms of users’ goals and what they need to do to achieve them

49. Theory of action (Norman, 1986)
specifies seven stages of an activity
Establish a goal
Form an intention
Specify an action sequence
Execute an action
Perceive the system state
Interpret the state
Evaluate the system state with respect to goals and intentions

50. An example: reading breaking news on the web
(i) Set goal to find out about breaking news
decide on news website
(ii) Form an intention
check out BBC website
(iii) Specify what to do
move cursor to link on browser
(iv) Execute action sequence
click on mouse button
(v) Check what happens at the interface
see a new page pop up on the screen
(vi) Interpret it
read that it is the BBC website
(vii) Evaluate it with respect to the goal
read breaking news
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51. In reality
Human activity does not proceed in such an orderly and sequential manner
More often the case that stages are missed, repeated or out of order
Users do not always have a clear goal in mind but react to the world, e.g. what appears on the screen

52. Theory of action
Theory is only approximation of what happens and is greatly simplified
Help designers think about how to help users monitor their actions in relation to their goals

53. Theory of action
Generally, the theory suggests the importance of providing feedback about the system state so that they can check whether their goals and intentions have been met
Examples:
Dialog boxes – remind users of possible intentions
Menus – allow users to browse, scan, and point at possible options

54. Gulf of execution
Difference between the intentions of the users and what the system allows them to do or how well the system supports those actions (Norman, 1988)

55. Gulf of evaluation
Degree to which the system/artifact provide representations that can be directly perceived and interpreted in terms of the expectations and intentions of the user (Norman, 1988)
“The gulf is small when the system provides information about its state in a form that is easy to get, is easy to interpret, and matches the way the person thinks of the system” (Norman, 1988)

56. Information processing

57. Information processing
Based on modeling mental activities that happen exclusively inside the head
However, most cognitive activities involve people interacting with external kinds of representations such as books, documents, and computers

58. External cognition & Distributed cognition
Study cognitive activities in the context in which they occur
Study how structures in the environment can both aid human cognition and reduce cognitive load

59. External cognition
Concerned with explaining the cognitive processes involved when we interact with different external representations
Explain cognitive benefits of using different representations
Externalizing to reduce memory load
Computational offloading
Annotating and cognitive tracing

60. Externalizing to reduce memory load
Diaries, reminders, calendars, notes, shopping lists, to-do lists - written to remind us of what to do
Post-its, piles, marked s - where place indicates priority of what to do
External representations:
Remind us that we need to do something (e.g. to buy something for mother’s day)
Remind us of what to do (e.g. buy a card)
Remind us when to do something (e.g. send a card by a certain date)

61. Computational offloading
When a tool is used in conjunction with an external representation to carry out a computation
Example: using pen and paper to solve a math problem
The kind of representation and tool used can change the nature of the task to being more or less easy

62. Computational offloading
Try doing the two sums below (a) in your head, (b) on a piece of paper and c) with a calculator.
234 x 456 =??
CCXXXIIII x CCCCXXXXXVI = ???
Which is easiest and why? Both are identical sums

63. Computational offloading
The kind of representation can transform a task into one that is easy or one that is difficult
Ex. Arabic numbers vs. roman numbers
The kind of tool used also can change the nature of the task to being more or less easy
Ex. Pen and paper vs. calculator

64. Annotating and cognitive tracing
Annotating involves modifying external representations through making marks
Ex. Crossing off or underlining items
Cognitive tracing involves externally manipulating items into different orders or structures
Ex. Creating different document piles to reflect the change of what needs to be done, playing cards

65. Design implications based on external cognition
Provide external representations at an interface that reduce memory load and facilitate computational offloading
Ex. Information visualizations,
Ex. GUI – wizards, dialog boxes guiding users through interactions

66. Distributed cognition
Studies the nature of cognitive phenomena across individuals, artifacts, and internal and external representations
Describes a ‘cognitive system’, which entails interactions among people, the artifacts they use, and the environment they are working in

67. Distributed cognition
Example:
Cognitive system: an airline cockpit
Interactions among people: pilot, co-pilot, air traffic controller
Interactions with artifacts: pilot, co-pilot, instruments in the cockpit
Interactions with the environment: pilot, co-pilot, runway, sky

68. Distributed cognition
Describes these interactions in terms of how information is represented and re-represented as it moves across individuals and through different artifacts
These transformations of information are referred to as changed in representational state

69. Distributed Cognition vs. Information processing
Focuses on what is happening inside the head of an individual
Distributed cognition
Focuses on what is happening across a system of individuals and artifacts

70. Distributed cognition analysis
The distributed problem-solving that takes place
The role of verbal and non-verbal behavior
The various coordinating mechanisms that are used (e.g., rules, procedures)
The communication that takes place as the collaborative activity progresses
How knowledge is shared and accessed

71. Key points
Cognition involves several processes including attention, memory, perception and learning
The way an interface is designed can greatly affect how well users can perceive, attend, learn and remember how to do their tasks
Theoretical frameworks such as mental models and external cognition provide ways of understanding how and why people interact with products, which can lead to thinking about how to design better products
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