Chapter 3 Understanding users

Outline What is cognition? Cognitive frameworks

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 From: www.id-book.com

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 From: www.id-book.com

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

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

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

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

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

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

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

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

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

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? From: www.id-book.com

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 From: www.id-book.com

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

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

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? From: www.id-book.com

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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)

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? From: www.id-book.com

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 From: www.id-book.com

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! From: www.id-book.com

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

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

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

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

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 From: www.id-book.com

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

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

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

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)

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)

Information processing

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

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

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

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 emails - 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)

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

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

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

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

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

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

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

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

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

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

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 From: www.id-book.com