Human Abilities Flashcards
What are the two components for understanding users?
- Needs with respect to specific system being designed (expertise, tasks, procedures, context-of-use)
- Fundamental human characteristics (vision, memory, cognition)
What are the components for the simplified view to describe fundamnetal human characteristics?
A simplified view involves:
- Input/out
- Memory
- Processing (cognition, problem solving, learning)
- Information i/o : perception (visual, auditory, haptic(input), movement, voice(output))
- Information stored in memory: sensory, short-term, long-term
- Information processed and applied: cognition, problem solving, skill, error
- Emoition/environmnet influence human capabilities
Each person is different
I/O: What is perception?
What are the two broad stages in vision?
- Physical reception of stimulus
- processing and interpretation of stimulus
- size and depth
- color
- patterns
How does the eye handle physical reception?
How does the eye handle and interprit size and depth?
What is Hue, Saturation and lightness?
What is the process for interpreting the signal for color?
How does color sensitivity work?
Why shouldn’t you rely on blue for text or small objects for an aging population?
What is the most common form of color-blindness?
What is contrast good for?
How does the human eye interpret patterns?
What are the Gestalt princples of perception?
- proximity
- similarity
- continuity
- closure
- area
- symmetry
What is the Gestaly principle: Proximity?
Items that are closer together will appear to belong together as compared to items that are further away.
What is the Gestalt princple of similarity?
Similarity: Items that share basic visual characteristics will be seen as belonging together:
Similarity in:
- size
- color
- texture
- orientation
Similarity helps a reader group similar objects or to recognize patterns in meaning.
Breaking similarity for contrast: Differences in size, shape or color help to distinguish elements from on another (break grouping) <- use this sparingly, and where noticing something is a desirable thing
What is the Gestalt principle of continuity?
Continuity: items arranged on a line or smooth curve are percieved to be related more.
What is the Gestalt princple of closure?
Closer: We tend to see complete figures even when part of the information is missing
Visual system will “fill in” the holes
What is the Gestalt principle of area?
Area: The smaller of two overlapping figures is perceived as figure while the larger is regarded as ground
Figure: element that is interpreted as object of interest
Ground: area on which figure rests
What is the Gestalt principle of symmetry?
Symmetry: Symmetrical, unconnected element are integrated into one coherent object
Symmertry accross a page helps to see it as a whole.
We simplify complex forms into simple shapes, based on symmetry
In general provide a summary of Gestalt princples in design
Provide a review for Vision
Why is Memory, Cognition and Learning important to consider in HCI?
Interacting with technology is cognitive
Need to take into account cognitive theories in HCI and cognitive limitations of users
Provides insight into what users can and cannot be expected to do
Helps identify and explain the nature and causes of problems users encounter
We are better at recognition than recall and better at remember images than words, what are the implications?
We are much better at recognition than recall
IMPLICATION: rise of the GUI over command- line interfaces
Better at remembering images than wordsIMPLICATION: use of icons rather than names
What are the 3 types of memory?
- Sensory
- Short-term
- Long-term
What are the channels of each sensory stimulus and what is the buffer?
One buffer for each channel:
- Iconic memory for visual
- Echoic memory for aural
- Haptic memory for touch
Implications?
Very temporary:
information constantly over-written/destroyed
How ins information passed from sensory to short-term memory? What does it depend on?
Information is passed from sensory memory to short-term memory through attention
Which stimuli we attend to depends on:
- Arousal
- Interest
- Need
In general, what is short-term memory, what does it act like and what is it’s access and decay rates?
A.k.a. working memory
Acts as a temporary “scratch pad” for temporary recall
Rapid access (~70ms), rapid decay (~200 ms)
Interference often causes disturbances in short- term memory retention
How many items can be held in short-term memory?
The rule of 7 +- 2 chunks
chunk: any meaningful combination of items
With good chunking, short-term memory is essentially unlimited
E.g.
CAT DOG PIG CLOCK (n=4 chunks)
ATD OGP IGC LOCKC (n=14 chunks)
In general, what are the details for long-term memory? How does information move to long-term memory?
Long-term store of facts, experiential knowledge, procedures
Unlimited capacity
Slow access time (~0.1 second)
Slow or no decay
Information moves from short- to long-term memory through rehearsal
What are the forms of long-term memory?
-
Episodic memory:
- represents our memory of events and experiences in a serial form
- from this memory we reconstruct the actual events that took place at a given point in our lives
- Semantic memory:
- structured record of facts and concepts that we have acquired
- information is derived from that in our own episodic memory, such that we can learn new facts or concepts from our experiences
In Long-term Memory, what helps us remember and what can cause us to “forget”
What helps us remember?
- Meaning
- Adding new information to existing memory structures
- Categories
- Pictures
- Cues - provided during the phase of encoding
- Spacing
What causes us to “forget”?
- Interference
- Retroactive interference
- New information masks old
- Proactive inhibition
- Old information leaks through
- Retroactive interference
- Do we actually forget, or do we forget have to remember that information?
How do you reduce memory load?
What is the definition of Cognition?
“of, relating to, being, or involving conscious intellectual activity (as thinking, reasoning, or remembering )”
What are the levels cognition occurs on?
Conscious Cognition:
- Our focus of attention
- Serial processor
- Attend to one thing at a time
- Short-term memory
- Low bandwidth
- limited information that an be processed at one time
Unconscious Cognition:
- Parallel processing
- do many things simutaneously (walk and chew gum)
- Higher bandwidth
- Long-term memory
What are the Conscious and Unconscious details of the following table:
How does learning relate to cognition
As we learn new things, they are pushed down from our conscious to unconcious levels of cognition.
Things become “automatic” once we learn them:
Driving a car:
Initially difficult to coordinate both hands and feet Requires full cognitive attention
In time, becomes more or less automatic Can instantly brake, accelerate
Typing:
Initially requires full cognitive attention
Over time, “pushed down” the stack to unconscious levels of cognition
What does ballistic and novel mean in the context of leanring?
Novel actions must be explicitly guided by conscious effort and feedback
Over time, actions become automatic, “ballistic”
Once you start an action, it executes to completion
Not under conscious control
Not as much feedback required by interface
On a spectrum, what aspects of it are under conscious, cognitive control, and which are “ballistic”?
Writing a Research Paper Example:
What is process of writing a paper?
- Decide on research paper topic
- Conscious
- Decide to search a range of databases
- Conscious
- Use mouse, keyboard to navigate to online database
- Motor actions are ballistic
What are the implications for design for concious and unconscious cognition?
Need to be careful what habits we encourage
- Confirmation dialogs with options in same place will lead to people automatically dismissing them
- In what situations is this undesirable, and how do designers work around this problem?
Consistency and congruency in interfaces help draw upon unconscious cognition
- Help reduce cognitive effort required for learning
What are the processes that transfer information between stores?
Sensory -> short-term
Short-term -> long-term
long-term -> short-term
Sensory -> short-term: attention
Short-term -> long-term: rehearsal, encoding
Long-term -> short-term: recall
