INFX 210 Ull chaudry test 2
Automated Data Input Devices
records data while reducing errors
Multimedia Input Devices
register input of human data (vision, sound, touch)
Constraints
The design concept of constraining refers to determining ways of restricting the kind of user interaction that can take place at a given moment. There are various ways this can be achieved.
Vision and Brain
Two eyes - Stereo Vision - Left and right visual fields 'crossover' Two channels from eye to brain - Visual Cortex - Conscious vision - Peripheral Cortex- Primitive responses (fear responses)
DESIGNING SENSORY AFFORDANCES
- Aesthetically pleasing designs - Increase user satisfaction and improve productivity - Beauty and utility may conflict - Mixed-up visual styles -> easy to distinguish - Clean design - little differentiation -> confusing - Backgrounds behind text - Good to look at but hard to read - But can work together - The consumer products - key differentiator (e.g. Apple)
Central vision (Fovea)
- Center of retina - Mainly cones - Very small => need saccades
Cones
- Central - Color (3 kinds) - Detailed vision (center of the eye) - Color vision - Bright light
DESIGNING PHYSICAL & SENSORY AFFORDANCES
- Color - Often used very badly!, - Need to be careful about overuse, combination, contrast (background color) - Best use - sparingly to reinforce other information - 3D - Good for physical information and some graphs - But bad if overused ... - e.g. text in perspective, 3D pie charts - angles in 3D confusing to decipher - Cultural Aspects - International issues e.g. languages, culture, sensitivities, symbols - Localisation issues, e.g. languages, cultural
Feedback
- Feedback is about sending back information about what action has been done and what has been accomplished, allowing the person to continue with the activity. Various kinds of feedback are available for interaction design-audio, tactile, verbal, and combinations of these.
Peripheral Vision (Periphery)
- Mainly rods - Detect movement => catch attention
Mezzanine Memory
- Memory of the past few hours or minutes - Not well studied -- knowledge is missing - What you are doing now? - Context -- activates LTM - Rehearsal -- commits it to LTM - What have you been doing recently? - Short-term episodic memory - (dream world -- mental world)
HYBRID DEVICES (INPUT + OUTPUT)
- Modems - Network cards - Touch Screen - Facsimile (FAX) machine - Audio Cards/Sound Card - Headsets
OUTPUT (& Storage) Devices
- Monitor (LED, LCD, CRT etc) - Printers (all types) - Plotters (Large format printers) - Projector - LCD Projection Panels - Computer Output Microfilm (COM) - Speaker(s) - Head Phone - Visual Display Unit - Film Recorder - Microfiche - Punch card puncher - Magnetic tape driver - 3D Printers
Rods
- Peripheral - Grey only (no color) - Movement - Dim light (less detail)
DESIGNING COGNITIVE AFFORDANCES
- Present information to match purpose - Sort order - Text vs diagram (Which font? Which diagram?) - Icons vs textual labels Paper presentation principles but add interactivity - Soften design choices - Allow movement of text e.g. reordering of columns - Interactive diagrams - What other kinds of interactivity can you do? - Limit interactivity
Long-term Memory
- Repository of all our knowledge - Our memory of who we are - Slow access - relative to STM - Slowly created = rehearsal - Slow decay, if any - Huge or unlimited capacity
WHAT WE REALLY SEE
- Sometimes what we think we are seeing is not what we are seeing ... optical illusion - Our brain tries to see things as if they were in the real world
Short-term Memory
- This is your thinking where your moment-to-moment thoughts are held - Known as the working memory (holds information you are currently dealing with) - Neurons firing ... electrical activity in your brain - Scratch-pad for temporary recall - Rapid access ~ 70 ms - Rapid decay ~ 200 ms - Limited time ~ 30 s without rehearsal - Limited capacity ~ 7+-2 chunks
Sensory memory
- about the senses not thinking - continuously overwritten - always sense change
Combination (output)
- all or some of the above aggregated together
Physical
- printed on paper or transparencies
Understand human behavior and thinking to
- shape technology designs, - understand how to evaluate technologies - make technologies usable, safe, and effective
Graphical
- tables, photos and drawings
Multimedia
- voice, video, physical
INPUT DEVICES
-Graphics Tablets - Cameras - Video Capture Hardware - Trackballs - Barcode reader - Digital camera - Gamepad - Joystick - QWERTY Keyboard - Microphone - MIDI keyboard - Mouse (pointing device) - Chip Card Reader - Scanner - Webcam - Touchpads - Pen Input - Microphone - Electronic Whiteboard - Optical Mark Reader (OMR) - Optical Character Recognizer (OCR) - Punch Card Reader - Magnetic Ink Character Reader - Magnetic Tape Reader
Shneiderman's 8 Golden Rules (1987)
1. Strive for consistency 2. Enable frequent users to use shortcuts 3. Offer informative feedback 4. Design dialog to yield closure 5. Offer error prevention and simple error 6. Permit easy reversal of actions 7. Support internal locus of control 8. Reduce short-term memory load
Where does interaction design start?
1. The User Interface 2. The System Architecture 3. The Computer Program 4. None of the Above
Norman's 7 Principles (1988)
1. Use both knowledge in the world and knowledge in the head 2. Simplify the structure of tasks 3. Make things visible 4. Get the mappings right 5. Exploit the power of constraints, both natural and artificial 6. Design for error 7. When all else fails, standardize
Nielsen's 10 Usability Heuristics (1994)
1. Visibility of System Status 2. Match Between the System and the Real World 3. User Control and Freedom 4. Consistency and Standards 5. Error Prevention 6. Recognition Rather than Recall 7. Flexibility and Ease of Use 8. Aesthetic and Minimalist Design 9. Help Users Recognise, Diagnose, and Recover from Errors 10. Help and Documentation
HCI
= Interface design + Interface environment development
REAL WORLD REASONING
A cognitive process by which we attain belief ● Involves looking for reasons, conclusions, actions or feelings ● Examples ○ Guessing consequences of actions ○ Deducing from perception ○ Finding logic in one's life ● Helps make sense of the world (characterized by information overload) ● Makes humanity move forward
PHYSICAL AFFORDANCES designs
A design feature that facilitates or enables users to do their physical actions - Computer interfaces (buttons, scroll bars - size and location) • Clicking, touching, pointing, gesturing, and moving things - Physical device interface (handles, levers, knobs etc.) • Gripping, turning, moving things
INDUCTION
Deriving a general rule from specific case(s) or drawing inferences from the observations in order to make generalizations - Example: Lots of people like to eat broccoli. We can generalize this observation and say that every human likes broccoli.
Implications for User Interface Design
A more learnable interface would have smaller gulfs of execution and evaluation, so that the user's goals are closer to the system representation in a certain sense - easier to execute, and easier to compare. A user interface with good visibility and feedback have smaller gulfs of evaluation. An efficient user interface is about the whole cycle - the speed of execution and perception.
REASONING CATEGORIES
Abduction ● Deduction ● Induction ● Confirmation ● Satisfiction ● Cause-and-effect ● so on .
Principles/Rules/Heuristics
Abstract design rules - "An interface should be easy to navigate"
Four stages of computation:
Accept Information ● Process Data ● Produce an Output ● Store Results
Guidelines
Advice on how to achieve principle - May conflict; understanding theory helps resolve - "Use color to highlight links"
Study of information transfer between humans and computers
Although knowledge transfer between humans and computers take place through a user interface, HCI goes beyond designing screens and menus that are easier to use. It studies the reasoning behind building a specific functionality into computers and the long-term effects that systems will have on humans
DEDUCTION
Application of general rules to particular cases. A conclusion follows based on a known argument - Example: All men are mortal. Socrates is a man. Therefore, Socrates is mortal. Your reasoning is based on a known fact and is therefore true (the truth of the known fact is not in question)
User Goal
Desired Outcome/User Story
System Design Implications
Distributed Cognition ● Situated Action ● Extended Mind
Mapping
This refers to the relationship between controls and their effects in the world. Nearly all artifacts need some kind of mapping between controls and effects, whether it is a flashlight, car, power plant, or cockpit. An example of a good mapping between control and effect is the up and down arrows used to represent the up and down movement of the cursor, respectively, on a computer keyboard.
LOW-LEVEL ACTIONS
Automatic Reactions (world does something and you react) ○ Moving your hand out of the fire ○ Innate, born with it ○ Some actions are learned ● Thinking is involved (you want to do something to the world) ○ Hand-eye coordination is very important ○ Fitts' Law - Takes longer to click if smaller target etc. ○ Time ~ log (distance/size)
How Visual System function?
Central vision (Fovea) and Peripheral Vision (Periphery) Ultimately, central and periphery vision work together .... Very important from design point of view ...
World
Computer System
Two Kind of Sensors on the Retina
Cones and rods
TYPES OF INPUTS
Data Set of instructions Commands Human Input
REASON AND EMOTION
Emotions are essential for reasoning ● Regulate motivation and focus ● Regulate boredom
ABDUCTION
Explaining something that is experienced and observed in some way and where there is no existing knowledge to explain the phenomenon - Example: A woman walks into the restaurant and her clothes are wet. You reason it must be raining outside, even though it might not be true... she could have fallen into a lake
TYPES OF OUTPUTS
Hard Copy (Permanent) Soft Copy (non-Permanent)
Instrumentalism
Humans are in Control Technology is ultimately a neutral instrument. It's humans who set the goals. Technologies serve our goals.
Two Views of Technology
Instrumentalism and Determinism
Interoception
Internal senses concerned with sensing the world within us e.g. hunger, headaches, proprioception etc.
CLASSES OF INPUT DEVICES
Keyboard Pointing Devices Terminals Multimedia Input Devices Automated Data Input Devices Combination
Types of Memory -- Time spans of memory
Long-Term Memory Mezzanine Memory (hours and days)- /Short-Term Memory /Auditory Store /Visual Store
HIGH-LEVEL ACTIONS
Longer-term conscious planning and activity ● Norman's execution-evaluation cycle ○ User establishes the goal ○ Formulates intention ○ Specifies action at interface ○ Executes action ○ Perceives system state ○ Interprets system state ○ Evaluates system state with respect to goal
WHY NEED HCI TOOLS?
Low cost way to check assumptions about user requirements, modify early, save a lot later 63% of large software projects go over cost • users request changes after system deployment • developers overlook important tasks • users do not understand their own requirements • insufficient user-developer communication and understanding
GOOD FUNCTIONAL AFFORDANCE
Makes the action possible
GOOD COGNITIVE AFFORDANCE
Makes the interaction easy to understand/learn
GOOD PHYSICAL AFFORDANCE
Makes the product easy to use (effortless)
GOOD SENSORY AFFORDANCE
Makes the product enjoyable to use (pleasure)
Human Memory
Memory is the process by which - Information is encoded and stored - Information is retrieved Human memory is quite expansive
MILLERS 7+/-2
Miller found that people's ability to remember numbers begins to fall around 7 items(<7)
FITTS LAW
Model of human movement • The time taken to hit a target (e.g. a button, menu or icon on screen) is a function of the size of the target and the distance that has to be moved to the target • A larger target is easier to hit than a small one • A close target is easier to hit than a distant one Time (Dt ) to move your hand to a target of size S at distance D= Rt + Mt R t is reaction time (get hand moving-- cognitive level) Mt is movement time (bring hand to the point of action -- motor level) Mt = a + b log(D/S + 1) where log(D/S + 1) is the index of difficulty
Five Senses
Most computer systems address our senses of sight and sound Computer systems don't typically target smell and taste (hard to create artificial smells). 1. Sight 2. Sound 3. Smell 4. Touch 5. Taste distance at which these senses operate decreases down the list
CLASSES OF OUTPUT DEVICES
Physical Graphical Multimedia Combination
WHAT IS AFFORDANCE?
Physical characteristics of a device or interface that allow its operation. Design aspects of technologies that offer people various possibilities for using them. During an interaction a user performs cognitive, physical and sensory actions and requires affordances to help with each.
GOOD I/O DEVICE DESIGN
Provides an affordance to link stages of human information processing pathway
Gulf of Execution
Psychological and physical barriers to achieving a goal
Gulf of Evaluation
Psychological and physical phenomena that occurs when comparing the goal to system's response to user interaction
SATISFICTION
Searching through the available alternatives to find a good enough rather than a perfect solution (satisfy + suffice) - Example: To sew a patch onto a pair of jeans, a 4 inch long needle with a 3 mm eye is the best option. This needle is hidden in a haystack along with 1000 other needles varying in size from 1 inch to 6 inches. The first needle that can do the job should be used rather than searching for the best possible needle.
CONFIRMATION
Seeking confirmation of facts rather than falsification of evidence (look for additional confirmatory action) - Example: If lion is coming towards to eat you, you don't want to start reasoning about it. You just want to run away
Exteroception
Sensing the world around us (getting information from the outside world into us)
Sound in User Interfaces
Sound is probably the second most important sense. Particularly, important for speech. Speech and hearing are important for social environments Less used in user interfaces ● Partly because annoying for others ● Because less direction more diffuse ● Strength and weaknesses
Spectrum of Sounds
Sounds vary in ● Pitch (frequency) ● Volume ● Timbre .. the shape (kind of sounds, notes on different instruments) ● Violin versus big bass drum
Standards
Specific rules, measurable - "MondoDesktop links are RGB #1010D0"
EARLIER USER INTERFACES GUIDELINES
Standards for technological design have existed within the user interface community since ISO 9241. The following aspects were considered important ● Effectiveness - does it do the right thing? ● Efficiency - does it require minimum effort? ● Satisfaction - does it make you feel happy? Previously ignored => now most important
ERGONOMICS
Study of physical aspects of interfaces
Determinism
Technologies are in Control Technology determines society. It is controlling our lives
Visibility
The more visible functions are, the more likely users will be able to know what to do next. In contrast, when functions are "out of sight," it makes them more difficult to find and know how to use.
HOW DO I DESIGN GOOD AFFORDANCES?
There are a multitude of issues that you have to consider when designing good affordances in your systems such as : The web, the applications, and the physical devices
PHYSICAL AFFORDANCE
This is a design feature that helps, aids, supports, facilitates, or enables physically doing something. an example is: A button that is large enough so that users can click on it accurately
FUNCTIONAL AFFORDANCE
This is a design feature that helps, aids, supports, facilitates, or enables the user in doing something. An example is A system's internal ability to sort a series of numbers (invoked by user clicking the Sort button on the screen)
SENSORY AFFORDANCE
This is a design feature that helps, aids, supports, facilitates, or enables the user in sensing something. An example is: A label font size large enough to read easily
COGNITIVE AFFORDANCE
This is a design feature that helps, aids, supports, facilitates, or enables thinking and/or knowing about something. an example is: A button label that helps users in knowing what will happen when they click it
Consistency
This refers to designing interfaces to have similar operations and use similar elements for achieving similar tasks. In particular, a consistent interface is one that follows rules, such as using the same operation to select all objects. For example, a consistent operation is using the same input action to highlight any graphical object at the interface, such as always clicking the left mouse button.
USER EXPERIENCE & EMOTION
User Experience has become a major buzzword ● Our emotions are largely driven by our experiences of the physical world ● People use technologies to experience emotions ● Initially, technology was about getting connected to loved ones (phone) ● Now it is about maintaining a lifestyle
ACTIONS
We live to act - Our perception leads to thinking that leads to action - There is evidence that a lot of what we do happens before we even think about it
Combination (input)
all or some of the above aggregated together
Keyboard
allows entry of data
Human-Computer interaction
is a discipline concerned with the design, evaluation and implementation of interactive computing systems and with the study of major phenomena surrounding them.
modern definition of computer
is any machine involved in some sort of a computational activity or possessing. It has to have a microprocessor chip, a memory bank, a hard drive and some sort of input and output device. ie, apple watches, microwave, and smart chip
Cycle of interaction
perception then memory thinking then Action
Pointing Devices
point and click into the computer world
Terminals
usually works in concert with a keypad/board
LIMITATIONS OF FITT'S LAW
• Grouped targets that are too close lead to overshoot errors • Advantageous only in screens with huge real estates • Differing sizes conflict with consistency • Frequency-based widget arrangements may be less efficient to find things than logic-based arrangements • Pop-up menus not visible until activated • Speed-accuracy tradeoff - fast decision - more errors and vice versa
IMPLICATIONS FITT'S LAW
• Large targets and small distances between targets are advantageous • Screen elements should occupy as much of the available screen space as possible • The largest Fitts-based pixel is the one under the cursor (why?) • Screen elements should take advantage of the screen edge whenever possible (why?) • The edges of the screen have infinite depth and no targeting required • Steering tasks - moving linearly in a "tunnel" of length D and size S is more difficult than pointing
A design feature that facilitates or enables users to do their cognitive actions
• Thinking • Deciding • Learning • Understanding • Remembering • Knowing about things
The Ear
● Sensitives from ~20Hz to ~20 KHz ● Changes with aging ● Balance organs also in the inner ear Two ears -- Stereo sound => left-right direction Pinna (visible ear!) -- Directional Changes shape of sound => full 3D sound ● Sound is about vibration, movement, pressure waves! ● You cannot still the sound! ● Always about to change