CSE 310 HumanComputer Interaction Lecture 1 Introduction Human

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CSE 310 Human-Computer Interaction Lecture #1 Introduction & Human Prepared & Presented by Asst.

CSE 310 Human-Computer Interaction Lecture #1 Introduction & Human Prepared & Presented by Asst. Prof. Dr. Samsun M. BAŞARICI

Part 1 Introduction

Part 1 Introduction

Learning Objectives § Appreciate the need for this course § Understand the importance of

Learning Objectives § Appreciate the need for this course § Understand the importance of HCI

Some Definitions § User: an individual user, a group of users, or a sequence

Some Definitions § User: an individual user, a group of users, or a sequence of users in an organization, each dealing with some part of the task or process § Computer: any technology ranging from desktop computer to large scale computer systems, or embedded systems and process control systems § Interaction: communication between user and computer (direct or indirect)

Human-Computer Interaction (HCI)? § Multi-disciplinary subject, should ideally include knowledge from psychology, cognitive science,

Human-Computer Interaction (HCI)? § Multi-disciplinary subject, should ideally include knowledge from psychology, cognitive science, ergonomics, sociology, computer science, etc. § A successful product should be: �useful: accomplish what is required �usable: do it easily and naturally, without danger of error, etc. �used: make people want to use it, be attractive, engaging, fun, etc.

HCI (definition and importance) § HCI: is the set of processes and resources that

HCI (definition and importance) § HCI: is the set of processes and resources that users employ to interact with computers § Building the human computer interface requires 50 -70% of systems development effort § To users, the interface is the system § A study by Nielsen (2003) indicates that if corporations spend 10% of their development budget on usability, they can improve usability by 135%

The Importance of HCI § Another study found that 51% of major websites violate

The Importance of HCI § Another study found that 51% of major websites violate the most basic design guidelines. § These studies and more demonstrate that there is a need for a more systematic treatment of HCI in the development process and more HCI experts are needed.

When HCI fails, the system fails

When HCI fails, the system fails

The Importance of HCI § Organizations of HCI are growing rapidly § There are

The Importance of HCI § Organizations of HCI are growing rapidly § There are more new journals dedicated to HCI than any other information systems sub-discipline

Interdisciplinary nature and scope of HCI

Interdisciplinary nature and scope of HCI

Why study HCI? § To help make IS users more productive, § To help

Why study HCI? § To help make IS users more productive, § To help IS professionals develop more usable and successful systems, § To enhance organizational effectiveness, § To provide researchers with cohesive and cumulative knowledge for theory building, and, § To apply this theoretical knowledge to enhance real information systems.

Part 2 The Human

Part 2 The Human

Learning Objectives § Understand the principles of human information gathering, processing and storing

Learning Objectives § Understand the principles of human information gathering, processing and storing

The Human § Information i/o … �visual, auditory, haptic, movement § Information stored in

The Human § Information i/o … �visual, auditory, haptic, movement § Information stored in memory �sensory, short-term, long-term § Information processed and applied �reasoning, problem solving, skill, error § Emotion influences human capabilities § Each person is different

The Brain § The center of all consciousness and also unconsciousness § Anatomy:

The Brain § The center of all consciousness and also unconsciousness § Anatomy:

Neurons § Cells of the brain

Neurons § Cells of the brain

Model Human Processor § 1983: Card, Moran, Newell § Simplified view of human processing

Model Human Processor § 1983: Card, Moran, Newell § Simplified view of human processing involved in interacting with computer systems § Three subsystems (sometimes also known as processors): �Perceptual system �Motor system �Cognitive system

Model Human Processor (cont) § (Three) Two types of memory: �(Sensory memories: Iconic, Echoic,

Model Human Processor (cont) § (Three) Two types of memory: �(Sensory memories: Iconic, Echoic, Haptic) �Working memory (also known as short-term memory, STM) �Long-term memory (LTM) § Following figure presents a simplified model of Human Information Processing which includes processors and memories that interact in order to process information.

A Simplified View of Human Information Processing (HIP) A simplified model of Human Information

A Simplified View of Human Information Processing (HIP) A simplified model of Human Information Processing (HIP), including memories and processor.

A Simplified View of Human Information Processing (HIP) (cont) § Performance: the speed and

A Simplified View of Human Information Processing (HIP) (cont) § Performance: the speed and accuracy of the informationprocessing task. § Automatic behavior: behavior characterized by cognitive processes that are fast and cognitively undemanding. § Controlled behavior: behavior characterized by cognitive processes that are relatively slow and cognitively demanding.

A Simplified View of Human Information Processing (HIP) (cont) § Processing of Images: processing

A Simplified View of Human Information Processing (HIP) (cont) § Processing of Images: processing characterized as spatial, graphic, and holistic. § Processing of verbal information: processing characterized as sequential, linguistic, and procedural. § Memory Aids �Heuristics: rules of thumb that depend heavily on the content and context of the task. �Metaphor: a cognitive process in which an experience is related to an already familiar concept. �Mental model: a representation of the conceptual structure of a device or a system.

Major Senses § § § Sight Hearing Touch Taste Smell First three important for

Major Senses § § § Sight Hearing Touch Taste Smell First three important for HCI

People remember 10% of what they read 20% of what they hear 30% of

People remember 10% of what they read 20% of what they hear 30% of what they see 50% of what they hear and see 80% of what they hear, see and say 90% of what they hear, see, say and touch

Vision Two stages in vision • physical reception of stimulus (eye) • processing and

Vision Two stages in vision • physical reception of stimulus (eye) • processing and interpretation of stimulus (mainly Colliculi superiors)

The Eye - physical reception § mechanism for receiving light and transforming it into

The Eye - physical reception § mechanism for receiving light and transforming it into electrical energy § light reflects from objects § images are focused upside-down on retina § retina contains rods for low light vision and cones for colour vision § ganglion cells (brain!) detect pattern and movement

Light § Some physics:

Light § Some physics:

The Eye (Anatomy)

The Eye (Anatomy)

The Eye (Anatomy) 1: posterior chamber 2: ora serrata 3: ciliary muscle 4: ciliary

The Eye (Anatomy) 1: posterior chamber 2: ora serrata 3: ciliary muscle 4: ciliary zonules 5: canal of Schlemm 6: pupil 7: anterior chamber 8: cornea 9: iris 10: lens cortex 11: lens nucleus 12: ciliary process 13: conjunctiva 14: inferior oblique muscle 15: inferior rectus muscle 16: medial rectus muscle 17: retinal arteries and veins 18: optic disc 19: dura mater 20: central retinal artery 21: central retinal vein 22: optic nerve 23: vorticose vein 24: bulbar sheath 25: macula 26: fovea 27: sclera 28: choroid 29: superior rectus muscle 30: retina

Interpreting the signal § Size and depth �visual angle indicates how much of view

Interpreting the signal § Size and depth �visual angle indicates how much of view object occupies (relates to size and distance from eye) �visual acuity is ability to perceive detail (limited) �familiar objects perceived as constant size (in spite of changes in visual angle when far away) �cues like overlapping help perception of size and depth

Interpreting the signal (cont) § Brightness � subjective reaction to levels of light �

Interpreting the signal (cont) § Brightness � subjective reaction to levels of light � affected by luminance of object � measured by just noticeable difference � visual acuity increases with luminance as does flicker § Colour � made up of hue, intensity, saturation � cones sensitive to colour wavelengths � blue acuity is lowest � 8% males and 1% females colour blind

Interpreting the signal (cont) § The visual system compensates for: �movement �changes in luminance.

Interpreting the signal (cont) § The visual system compensates for: �movement �changes in luminance. § Context is used to resolve ambiguity § Optical illusions sometimes occur due to over compensation

Optical Illusions the Ponzo illusion the Muller Lyer illusion

Optical Illusions the Ponzo illusion the Muller Lyer illusion

Optical Illusions (cont) �Overstimulating the visual processing system: like the afterimage you get when

Optical Illusions (cont) �Overstimulating the visual processing system: like the afterimage you get when you stare foolishly into the sun (against your mother’s advice)

Optical Illusions (cont) �Saccades: Quick, rapid eye movements Rotating snakes by Akiyoshi Kitaoka

Optical Illusions (cont) �Saccades: Quick, rapid eye movements Rotating snakes by Akiyoshi Kitaoka

Optical Illusions (cont) �Distortions: Zöllner Illusion

Optical Illusions (cont) �Distortions: Zöllner Illusion

Optical Illusions (cont) �Faulty comparisons:

Optical Illusions (cont) �Faulty comparisons:

Optical Illusions (cont) �Seeing things: Pattern recognition in brain What do you read here?

Optical Illusions (cont) �Seeing things: Pattern recognition in brain What do you read here? I LIKE JUMPING TO CONCLUSIONS Or L IIKE IUMRING TQ GQNGIUSIQNS (In second case you have a perverse sense of humor)

What do you see? �Can you trust your brain?

What do you see? �Can you trust your brain?

What do you see? �Can you trust your brain?

What do you see? �Can you trust your brain?

Reading § Several stages: � visual pattern perceived � decoded using internal representation of

Reading § Several stages: � visual pattern perceived � decoded using internal representation of language � interpreted using knowledge of syntax, semantics, pragmatics § § Reading involves saccades and fixations Perception occurs during fixations Word shape is important to recognition Negative contrast improves reading from computer screen

Hearing § Provides information about environment: distances, directions, objects etc. § Physical apparatus: �

Hearing § Provides information about environment: distances, directions, objects etc. § Physical apparatus: � outer ear � middle ear � inner ear – protects inner and amplifies sound – transmits sound waves as vibrations to inner ear – chemical transmitters are released and cause impulses in auditory nerve § Sound � pitch � loudness � timbre – sound frequency – amplitude – type or quality

Hearing (cont) § Humans can hear frequencies from 20 Hz to 15 k. Hz

Hearing (cont) § Humans can hear frequencies from 20 Hz to 15 k. Hz � less accurate distinguishing high frequencies than low. § Auditory system filters sounds � can attend to sounds over background noise. � for example, the cocktail party phenomenon.

Touch § Provides important feedback about environment. § May be key sense for someone

Touch § Provides important feedback about environment. § May be key sense for someone who is visually impaired. § Stimulus received via receptors in the skin: � thermoreceptors � nociceptors � mechanoreceptors – heat and cold – pain – pressure (some instant, some continuous) § Some areas more sensitive than others e. g. fingers. § Kinethesis - awareness of body position � affects comfort and performance.

Movement § Time taken to respond to stimulus: reaction time + movement time §

Movement § Time taken to respond to stimulus: reaction time + movement time § Movement time dependent on age, fitness etc. § Reaction time - dependent on stimulus type: � visual � auditory � pain ~ 200 ms ~ 150 ms ~ 700 ms § Increasing reaction time decreases accuracy in the unskilled operator but not in the skilled operator.

Movement (cont) § Fitts' Law describes the time taken to hit a screen target:

Movement (cont) § Fitts' Law describes the time taken to hit a screen target: Mt = a + b log 2(D/S + 1) where: a and b are empirically determined constants Mt is movement time D is Distance S is Size of targets as large as possible distances as small as possible

Memory There are three types of memory function: Sensory memories Short-term memory or working

Memory There are three types of memory function: Sensory memories Short-term memory or working memory Long-term memory Selection of stimuli governed by level of arousal.

sensory memory § Buffers for stimuli received through senses �iconic memory: visual stimuli �echoic

sensory memory § Buffers for stimuli received through senses �iconic memory: visual stimuli �echoic memory: aural stimuli �haptic memory: tactile stimuli § Examples �“sparkler” trail �stereo sound § Continuously overwritten

Short-term memory (STM) § Scratch-pad for temporary recall �rapid access ~ 70 ms �rapid

Short-term memory (STM) § Scratch-pad for temporary recall �rapid access ~ 70 ms �rapid decay ~ 200 ms �limited capacity - 7± 2 chunks

Examples 212348278493202 0121 414 2626 HEC ATR ANU PTH ETR EET

Examples 212348278493202 0121 414 2626 HEC ATR ANU PTH ETR EET

Model of STM (Baddeley) Visuo-spatial scratch-pad Articulatory Loop Central Executive Auditory imaging system

Model of STM (Baddeley) Visuo-spatial scratch-pad Articulatory Loop Central Executive Auditory imaging system

Long-term memory (LTM) § Repository for all our knowledge � slow access ~ 1/10

Long-term memory (LTM) § Repository for all our knowledge � slow access ~ 1/10 second � slow decay, if any � huge or unlimited capacity § Two types � episodic � semantic – serial memory of events – structured memory of facts, concepts, skills semantic LTM derived from episodic LTM

Long-term memory (cont. ) § Semantic memory structure � provides access to information �

Long-term memory (cont. ) § Semantic memory structure � provides access to information � represents relationships between bits of information � supports inference § Model: semantic network � inheritance – child nodes inherit properties of parent nodes � relationships between bits of information explicit � supports inference through inheritance

LTM - semantic network

LTM - semantic network

Models of LTM - Frames § Information organized in data structures § Slots in

Models of LTM - Frames § Information organized in data structures § Slots in structure instantiated with values for instance of data § Type–subtype relationships DOG Fixed legs: 4 Default diet: carniverous sound: bark Variable size: colour COLLIE Fixed breed of: DOG type: sheepdog Default size: 65 cm Variable colour

Models of LTM - Scripts Model of stereotypical information required to interpret situation Script

Models of LTM - Scripts Model of stereotypical information required to interpret situation Script has elements that can be instantiated with values for context Script for a visit to the vet Entry conditions: dog ill vet open owner has money Result: dog better owner poorer vet richer Props: examination table medicine instruments Roles: vet examines diagnoses treats owner brings dog in pays takes dog out Scenes: arriving at reception waiting in room examination paying Tracks: dog needs medicine dog needs operation

Models of LTM - Production rules Representation of procedural knowledge. Condition/action rules if condition

Models of LTM - Production rules Representation of procedural knowledge. Condition/action rules if condition is matched then use rule to determine action. IF dog is wagging tail THEN pat dog IF dog is growling THEN run away

LTM - Storage of information § rehearsal � information moves from STM to LTM

LTM - Storage of information § rehearsal � information moves from STM to LTM § total time hypothesis � amount retained proportional to rehearsal time § distribution of practice effect � optimized by spreading learning over time § structure, meaning and familiarity � information easier to remember

LTM - Forgetting decay � information is lost gradually but very slowly interference �

LTM - Forgetting decay � information is lost gradually but very slowly interference � new information replaces old: retroactive interference � old may interfere with new: proactive inhibition so may not forget at all memory is selective … … affected by emotion – can subconsciously `choose' to forget

LTM - retrieval recall � information reproduced from memory can be assisted by cues,

LTM - retrieval recall � information reproduced from memory can be assisted by cues, e. g. categories, imagery recognition � information gives knowledge that it has been seen before � less complex than recall - information is cue

Thinking deduction, induction, abduction Problem solving

Thinking deduction, induction, abduction Problem solving

Deductive Reasoning § Deduction: � derive logically necessary conclusion from given premises. e. g.

Deductive Reasoning § Deduction: � derive logically necessary conclusion from given premises. e. g. If it is Friday then she will go to work It is Friday Therefore she will go to work. § Logical conclusion not necessarily true: e. g. If it is raining then the ground is dry It is raining Therefore the ground is dry

Deduction (cont. ) § When truth and logical validity clash … e. g. Some

Deduction (cont. ) § When truth and logical validity clash … e. g. Some people are babies Some babies cry Inference - Some people cry Correct? § People bring world knowledge to bear

Inductive Reasoning § Induction: � generalize from cases seen to cases unseen e. g.

Inductive Reasoning § Induction: � generalize from cases seen to cases unseen e. g. all elephants we have seen have trunks therefore all elephants have trunks. § Unreliable: � can only prove false not true … but useful! § Humans not good at using negative evidence e. g. Wason's cards.

Wason's cards 7 E 4 K If a card has a vowel on one

Wason's cards 7 E 4 K If a card has a vowel on one side it has an even number on the other Is this true? How many cards do you need to turn over to find out? …. and which cards?

Abductive reasoning § reasoning from event to cause e. g. Sam drives fast when

Abductive reasoning § reasoning from event to cause e. g. Sam drives fast when drunk. If I see Sam driving fast, assume drunk. § Unreliable: �can lead to false explanations

Problem solving § Process of finding solution to unfamiliar task using knowledge. § Several

Problem solving § Process of finding solution to unfamiliar task using knowledge. § Several theories. § Gestalt � problem solving both productive and reproductive � productive draws on insight and restructuring of problem � attractive but not enough evidence to explain `insight' etc. � move away from behaviourism and led towards information processing theories

(Some) Gestalt Laws § Law of Conciseness:

(Some) Gestalt Laws § Law of Conciseness:

(Some) Gestalt Laws (cont) § Law of Similarity:

(Some) Gestalt Laws (cont) § Law of Similarity:

(Some) Gestalt Laws (cont) § Law of Proximity:

(Some) Gestalt Laws (cont) § Law of Proximity:

(Some) Gestalt Laws (cont) § Law of Continuity:

(Some) Gestalt Laws (cont) § Law of Continuity:

(Some) Gestalt Laws (cont) § Law of Closure:

(Some) Gestalt Laws (cont) § Law of Closure:

(Some) Gestalt Laws (cont) § Law of Experience:

(Some) Gestalt Laws (cont) § Law of Experience:

(Some) Gestalt Laws (cont)

(Some) Gestalt Laws (cont)

(Some) Gestalt Laws (cont)

(Some) Gestalt Laws (cont)

Problem solving (cont. ) Problem space theory � problem space comprises problem states �

Problem solving (cont. ) Problem space theory � problem space comprises problem states � problem solving involves generating states using legal operators � heuristics may be employed to select operators e. g. means-ends analysis � operates within human information processing system e. g. STM limits etc. � largely applied to problem solving in well-defined areas e. g. puzzles rather than knowledge intensive areas

Problem solving (cont. ) § Analogy � analogical mapping: � novel problems in new

Problem solving (cont. ) § Analogy � analogical mapping: � novel problems in new domain? � use knowledge of similar problem from similar domain � analogical mapping difficult if domains are semantically different § Skill acquisition � skilled activity characterized by chunking � lot of information is chunked to optimize STM � conceptual rather than superficial grouping of problems � information is structured more effectively

Errors and mental models Types of error § slips � � � right intention,

Errors and mental models Types of error § slips � � � right intention, but failed to do it right causes: poor physical skill, inattention etc. change to aspect of skilled behaviour can cause slip § mistakes � � wrong intention cause: incorrect understanding humans create mental models to explain behaviour. if wrong (different from actual system) errors can occur

Emotion § Various theories of how emotion works � James-Lange: emotion is our interpretation

Emotion § Various theories of how emotion works � James-Lange: emotion is our interpretation of a physiological response to a stimuli � Cannon: emotion is a psychological response to a stimuli � Schacter-Singer: emotion is the result of our evaluation of our physiological responses, in the light of the whole situation we are in § Emotion clearly involves both cognitive and physical responses to stimuli

Emotion (cont. ) § The biological response to physical stimuli is called affect §

Emotion (cont. ) § The biological response to physical stimuli is called affect § Affect influences how we respond to situations � positive creative problem solving � negative narrow thinking “Negative affect can make it harder to do even easy tasks; positive affect can make it easier to do difficult tasks” (Donald Norman)

Emotion (cont. ) § Implications for interface design �stress will increase the difficulty of

Emotion (cont. ) § Implications for interface design �stress will increase the difficulty of problem solving �relaxed users will be more forgiving of shortcomings in design �aesthetically pleasing and rewarding interfaces will increase positive affect

Individual differences § long term – sex, physical and intellectual abilities § short term

Individual differences § long term – sex, physical and intellectual abilities § short term – effect of stress or fatigue § changing – age Ask yourself: will design decision exclude section of user population?

Psychology and the Design of Interactive System § Some direct applications � e. g.

Psychology and the Design of Interactive System § Some direct applications � e. g. blue acuity is poor blue should not be used for important detail § However, correct application generally requires understanding of context in psychology, and an understanding of particular experimental conditions § A lot of knowledge has been distilled in � guidelines � cognitive models � experimental and analytic evaluation techniques

Next Lecture The Computer

Next Lecture The Computer

References § Alan Dix, Janet Finlay, Gregory D. Abowd, Russell Beale, “Human-Computer Interaction, 3

References § Alan Dix, Janet Finlay, Gregory D. Abowd, Russell Beale, “Human-Computer Interaction, 3 rd Edition”, Prentice Hall, 2004, ISBN: 0 -13 -046109 -1 § Douglas Whitman, “Cognition, 1 st Ed. ”; Wiley & Sons, 2010, ISBN: 978 -0471715665 § Margaret W. Matlin, “Cognitive Psychology, International Student Version, 7 th Ed. ”, Wiley & Sons, 2008, ISBN: 978 -0470409473 § Thomas Ditzinger, “Illusionen des Sehens, 2 nd Ed. ”, Springer Spektrum, 2013, ISBN: 978 -3 -642 -37711 -2 § Matthew Mac. Donald, “Your Brain, The Missing Manual, 1 st Ed. ”, O’Reilly, 2008, ISBN: 978 -0 -596 -51778 -6