I


human - computer interaction is a discipline concerned with the
	-DESIGN
	-EVALUATION
	-IMPLEMENTATION
	of interactive computing systems for human use and with the study of major phenomena surrounding them.


human :
	- information processing
	- language, communication
	ergonomics

computer :
	- interface metaphors
	- dialogue techniques
	- I/O devices
	- Graphic design

evaluation techniques -> design approaches <> prototypes -> implementation techniques and tools
that's the development process


form:
even in 1989 there was a form infrastructure

aplication : | ping telnet ftp smtp | trace route | dns snmp nfs |
transport  :        |      tcp      |             |      udp     |
network    : | ICMP |                 IP                         |  IGMP |
access to network : ARP - DATA CONNECTION - RARP
						environment



Tim Berners-Lee - implemented interface to the hipertext (HTTP)


We want the system to be
- useful => effective: meets objectives and requirement
- usable => efficient: easy, intuitive, secure
- used   => attractive: nice and rewarding

david wargo - author of switch panel


three mile island - 1 april 1979

valve -> core to overheat -> emergency valve -> leakage of radioactive water vapor

The main factor that turned this incidend into an accident was incorrect
reaction of the operators

in the first few minutes 100 to 200 alarmes sounded


in practise we will do things in javaFX scene builder in netbeansx

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II

the human user = information processing unit (IPU)
(morgan & newell 1983)


cognitive psychology :
	- perceptive system
	- motor system
	- cognitive system


Cognitive psychology
Create for human usage :
	- aware of capacities and limitations
	- what is easy and difficult?
	- what is pleasant?
	- main user modus operandi.


information input / output
	- visual, hearing, haptic, movement
information stored in memory
	-sensorial, short and long term
information processed and applied
	- reasoning, problem solving, skills, error
the emotional dimension
the uniques of each person

input - through the sense

vision
involves two steps:
	- physical reception of a stimulus
	- interpretation and processing

EYE - the reception of a stimulus (odbior bodzca)

- light RECEIVED and transformed into electrical signals - odbierane i przetransformowane w sygnaly elektryczne
- light EMITTED and REFLECTED by objects - swiatlo emitowane i odbijane od obiektow
- the RETINA focus images upside down (siatkówka)
- the retina contains two kind of photoreceptors:
	-Rods(bastonetes) - luminosity sensitivity (pręty - wrazliwe na jasnosc)
	-Cones - chromatic vision (syszki - chromatyczne widzenie)
- the GANGLION cells detects PATTERNS (X in foeva) and MOVEMENT (Y peripheral).

Rods(bastonetes) ~ 120 millions
	- in the retina extermities
	- peripheral vision

Cones ~ 6 milions
-there are three kind
-concentrated in the foeva

Ganglions
-X-cells ~> patterns
-Y-cells ~> movement




signal interpretation

size - measuring the visual angle: degrees, minutes, and arc seconds:
	- SAME SIZE objects at different distances have different visual angles
	- DIFFERENT SIZE objects, positioned at the right different distances
	  will have the same visual angle, in the eye of the observer.


correct assessment requires observer's world knowledge

visual acuity
	- the abillity of a person to percive the thinest details
	Example : perceive lines with the 0,5 arc seconds in width
	- perceive lines spaced 30 arc seconds

chromatic vision
	- the three components
		- hue - the spectral wavelength (average person: 150)
		- intensity - the color brightness
		- saturation - the amount of the whiteness in the color

	- perceive approximately 7 million colors
	- green ~ maximal acuity
	- blue ~ minimal acutiy (3% to 4% blue cones)
	- 8% men and 1% women have some kind of color perception deficiency - COLORBLIND
	 ( GREEN <> RED ? )

brightness
	- measures the light intesity
	- related with luminance, measured through a photometer
	- contrast: the ratio between two brightness levels
	- the pupil compensates for brightness variation
	- visual acuity increases with luminance

color hue
	hues can refer to the set of "pure" colors within a color space

visual processing
	- action of the brain on the significance of the visual signal input
	- what we see is an interpretation guided by our expectations
		- example the notion of constant size
	- our brain can infer complete images when there are "holes"
	- so, maybe . .  your mind can be deceived

optical illusions:
	- the law of size
		- the ponzo illusions
		- the muller lyer illusion


graphic design:
	- we tend to increase horizontal lines and shorten the vertical ones
	- the perceived "optical center" is positioned slightly above the true center

Text reading:

	- human eye makes rapid movementes (SACCADES) and pauses (FIXATIONS) - 94% time breaks
	- information is collected during the "fixations" and there are 3 to 5 per line of text
	- there are also REGRESSIONS in the eye movement
		- complex text = = more regressions
	- reading speed in adults 250 words / minute
	- reading from a computer is slower than from a book
	- dark letters on light background is easier to read - more luminance => greater acuity
	- font sizes: 9 = 12 if proportional spacing lines

	how do humans really read?
		- chinese ideogramas
		- there are about 42 000
		- only 3000 most used

Human Hearing:
	- usually considered as secondary, but...
	- there is much more information entering than the one we naively consider
	- the pinna acts as a tunnel that channels the sound into the ear
	- we were able to estimate distances, due to delays in reception between the two ears

hearing Provides rich envirement information:
 - distances, directions, etc.
 - physical apparatus
	- outer ear - protects inner and amplifies sound
	- middle ear - transmits sound waves as vibrations to inner ear
	- inner ear - chemical transmitters are released and cause impulses in auditory nerve

- sound
	- pitch - frequency (Hz)
	- loudness - amplitude (dB)
	- timbre - type or quality ( barwa dzwieku )

processing sound
	- human hearing range between 20Hz and 15kHz
		- dogs can hear ultrasounds
		- elephants communicate through infra-sounds
	- at low frequencies we can detect differences of 1.5 Hz
	- at higher frequencies, we lose sensitivity
	- the hearing range varies with age
	- the brain efficiently filter sounds - e. g. "the cocktail party"
	- there are also auditory illusions as well

touch
	- also known as "haptic perception"
	- normally used as an unconscious feedback
		- the keypressed, when we write
		- sensing the mouse location (kinaesthetic)
		- vibration in electronic equipment

	-stimuli through skin receptors:
		- mecano-receptors (pressure)
		- termo receptors (heat)
		- nocio-receptores (pain or intense pressure)
	- heterogeneous sensitivity:
		- the sensitivity of the findertip is about 10 times the sensitivity of the forearm

movement
	- the movement is composed of two essential characteristics:
		- speed
		- precision

	- speed ( reaction time) depends on two things ( e.g. accident):
		- processing time
		- movement time

	- time taken to respond to stimulus:
		reaction time + movement time
	- the reaction time - dependent on stimulus type:
		-visual ~200 ms
		-auditory ~150 ms            combined stimulus =
		-pain ~700ms

	- movement time dependent on age, fitness, etc

	- increasing reaction time decreases accuracy in the unskilled operator but not
	in the skilled operator

	Fit's Law ( 1954 )
	Describes the time taken to hit a screen target:
		Mt = a + b log 2(d/s +1)
		a and b - empirically determined constants
		Mt is the movement time
		D is the distance to target
		S is the size of the target

	- Rule: targets as large as possible and distance as small as possible

	- The reaction time increases with aging but can be improved through training
		Audio 150ms
		Visual 200ms
	- Low reaction time leads to low accuracy
	- Hands do not have the movement exclusivity

	The Hick's Law(1952)
	Models the time required to select one option among several possibilities:
	T = b log2(n+1)
		n is the number of possibilites
		t is the time taken to choose an option
		b is an empirical constant
	rule: always present the adequate number of choinces

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III

Memory
	stores facts, procedures , actions

	three types of memory:


	- sensory
	- short-term/working memory (STM)
	- long-term memory (LTM)


	sensory -> attention -> short-term -> rehearsal -> long-term

sensory :
	- buffers for stimuli received through senses

		- iconic memory: visual stimuli
		- echoic memory: aural stimuli
		- haptic memory: tactile stimuli

sensory -> attention -> short-term memory
attention is the action of focusing on a given item by filtering the remaining
inputs received at that time.
without this filtering we will rapidly become overwhelmed with information.


short-time memory
	- works as a scratch-pad for temporary recall
		- when we read
		- in mental calculations
	- temporary data storage
		- rapid access 70 ms
		- rapid decay 200 ms
		- finite and very limited 7 + - chunks.

On average, a person can remember 7+-2 items in his STM (Menus, Lists, Cmds)
but : there are many things that can easily be remebered.

Chunking is division into smaller meaningful pieces, increases memory usage efficiency.

Chunking leads to Closure. A failure in closure leads the user to lose mental location,
causing him to make MISTAKES. (e.g. ATM).


Long-Term memory (LTM)
	-repository for all our knowledge
		- slow access time ~ 100ms
		- slow decay (if any)
		- immense storage capacity
	-two types
		- episodic - memorize sequence of events (like when we hear a narrative).
		- semantic - memorize fact structures, concepts, skills, ... -
		like a graph model (or like classes with atributes in OOP).

	Structure of semantic memory:
		- facilitates the retrieval of information.
		- represents the relationship between two information units
		- supports inference and generalization.

Models of LTM:
	- semantic network
	- frames (type-subtype relationships, extension of a semantic network)
	- production rules (IF condition is verified, THEN action rules)

Two theories about forgetting:
	-decay (very slowly / ebbinghaus mowi ze logarytmicznie )
	jot's law : if two memories are equally strong the oldest last longer)

Interference
	- new information replaces old: retroactive interference
	- old may interfere with new: proactive inhibition (driving to our old house)
	- may not forget at all
	- affected by emotions

Reasoning:
	- Deductive (if ... then) logic thinking
	- Inductive - generalize things seen from unseen
	- Abductive - event -> action (unreliable)

Problem solving:
	- process of finding solution
Theories:
	- Behaviourism (reproductively + trial and error cycle)
	- Gestalt (non behaviorists) - productive and reproductive

Problem space theory - generates problem states using legal operators

Analogy - knowledge of similar problem
Skill acquisition - skilled by chunking (if then if and then) (np pieczenie ciasta)

Types of error
	- slips ( right intention but failed to do it right. caused: poor physical skill, inattention
	similar aspect but different functionality).
	- mistakes (wrong intention, cause : incorrect understanding)

People creates mental models to explain behavior and it can cause an error.


EMOTIONS
Implications for interface design:
	- stress increase the difficulty of problem solving
	- relaxed users will be more forgiving
	- aesthetically pleasing and rewarding interfaces will increase positive affect

	Individual Differences

- Long term (gender, physical and intellectual abilities)
- Short term (effect of stress or fatigue)
- Changing (age)

Interaction is what goes in and what goes out.

Qerty is not optimal and people are just used to it and don't want a change.

Alphabetic:
	- keys arranged in alpabetic order - not faster for anyone

Dvorak - 15% faster, biased towards right hand, common letters under dominant fingers

Shape Writer - based on fitt's law mt = a+b log2(d/s + 1)
more efficient

special keyboards:
 - for impaired users in general
 - for one hand usage
 - for reducing fatigue for RSI
 - laser projection keyboards
 - phone pad and t9 entry
 - numeric keypads
 - cursor keys

-handwriting recognition
- speech recognition (NLP)

-touchpads
-mouse
-direct touch

Multimodal Co-located Interaction - user exemplifies commands throught gestures
system uses voice and image recognition

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eyegaze

resolution - number of pixels (width x height) uhd 3840 x 2160 pda 240x400
ratio 4:3 for most screens / 16:9
color depth:
	- how many different colors for each pixel?
	- 256 from pallete, 8 bits each for red / green / blue = millions of colors

CRT - stream of electrons emitted from electron gun, focused and directed
by magnetic fields, hit phosphor coated screen which glows
- used in tvs and computer monitors

LCD - liquid crystal displays.
	top plate transparent and polarized, bottom plate reflecting
	light passes through top plate and crystal, and reflects back to eye
	voltage applied to crystal changes polarization and chence color
	light reflected not emitted => less eye strain

What is interaction?

Communication
User <=> System
task language - core language

Donald Norman's Model
1. user establishes the goal
2. formulates intention
3. specifies actions at interface
4. executes action
5. perceives system state
6. interprets sytem state
7. evaluates system state with respect to goal


Some system are harder to use than others WHY>!>!>!>>!?!!?!?!?\

Gulf of execution - user's formulation of actions =/= actions allowed by the system
Gulf of evaluation - user's expectations of changed system state =/= actual presetnation of this state

Human errors -> Slips and mistakes
slips :
understanding of the system
correct formula of goal
incorrect action

fix : better interface

mistakes
bad goal

fix : better understanding of the system


Abowd and Beale Framework - interaction framework
Extension of norman's model, their interaction framwerok has 4 parts
User
Input
System
Output

*System Core -> Output -> User -> Input -> *

presentation observation auticulation performance


What is design. It's achiving goals within constraints
Goals - purporse (who is it for, why do they want it)

Constraints materials, platforms
Trade-offs good vs. optimum

Understand materials - understand people , understand computer and their interaction

process of design

What is wanted? -> analysis -> design -> implementation and deploy
					-> prototypes <-


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					Scenarios
			- stories for design (communicate with others, validate other models, understand dynamics)
			- linearity - time is linear - our lives are linear

What would user want to do, how would they react to this?
step by step walkthrough (SEE DO THINKING).

also play and act (mock up device, pretend you are doing it.. internet connetcted swiss army knife)

explore interaction - what happens when
explore cognition - what are the users tihnking
explore architecture - what is happening inside

user scenarios to communicate with others, validate other models, express dynamics (screenshots, scenario)

scenarios - one linear path though the system
pros
+ life is linear and time is linear
+ easy to understand
+ concrete

- no choice no branches no special conditions
- miss the unintended

so
- use several scenarios
- user other methods

four levels of design
- widget choice (menu, buttons, labels, etc.)
- screen design ( find things, grouping )
- application navigation design
- environment

4 golden rules
know where you are
know what you can do
know where you are going
know where you've been or 've done

sacrifice form for the sake of function !


wider still
	- style issues: platform standards, consistency
	- functional issues: cut and paste
	- navigation issues ( links to others apps ... the web) embedded applications

basic principles
	- ask
		-what is the user doing
	- think
		- what information required?
		- comparisons to make?
		- order of things?
	- design
		- form follows function