Human Abilities

Question 1

What are the two components for understanding users?

Answer 1

1. Needs with respect to specific system being designed (expertise, tasks, procedures, context-of-use)
2. Fundamental human characteristics (vision, memory, cognition)

Question 2

What are the components for the simplified view to describe fundamnetal human characteristics?

Answer 2

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

Question 3

I/O: What is perception?

Answer 3

Question 4

What are the two broad stages in vision?

Answer 4

1. Physical reception of stimulus
2. processing and interpretation of stimulus
   
   1. size and depth
   2. color
   3. patterns

Question 5

How does the eye handle physical reception?

Answer 5

Question 6

How does the eye handle and interprit size and depth?

Answer 6

Question 7

What is Hue, Saturation and lightness?

Answer 7

Question 8

What is the process for interpreting the signal for color?

Answer 8

Question 9

How does color sensitivity work?

Answer 9

Question 10

Why shouldn’t you rely on blue for text or small objects for an aging population?

Answer 10

Question 11

What is the most common form of color-blindness?

Answer 11

Question 12

What is contrast good for?

Answer 12

Question 13

How does the human eye interpret patterns?

Answer 13

Question 14

What are the Gestalt princples of perception?

Answer 14

1. proximity
2. similarity
3. continuity
4. closure
5. area
6. symmetry

Question 15

What is the Gestaly principle: Proximity?

Answer 15

Items that are closer together will appear to belong together as compared to items that are further away.

Question 16

What is the Gestalt princple of similarity?

Answer 16

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

Question 17

What is the Gestalt principle of continuity?

Answer 17

Continuity: items arranged on a line or smooth curve are percieved to be related more.

Question 18

What is the Gestalt princple of closure?

Answer 18

Closer: We tend to see complete figures even when part of the information is missing

Visual system will “fill in” the holes

Question 19

What is the Gestalt principle of area?

Answer 19

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

Question 20

What is the Gestalt principle of symmetry?

Answer 20

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

Question 21

In general provide a summary of Gestalt princples in design

Answer 21

Question 22

Provide a review for Vision

Answer 22

Question 23

Why is Memory, Cognition and Learning important to consider in HCI?

Answer 23

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

Question 24

We are better at recognition than recall and better at remember images than words, what are the implications?

Answer 24

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

Question 25

What are the 3 types of memory?

Answer 25

1. Sensory 2. Short-term 3. Long-term

Question 26

What are the channels of each sensory stimulus and what is the buffer?

Answer 26

One buffer for each channel: 1. Iconic memory for visual 2. Echoic memory for aural 3. Haptic memory for touch **Implications?** Very temporary: information constantly over-written/destroyed

Question 27

How ins information passed from sensory to short-term memory? What does it depend on?

Answer 27

Information is passed from sensory memory to short-term memory through attention Which stimuli we attend to depends on: * Arousal * Interest * Need

Question 28

In general, what is short-term memory, what does it act like and what is it's access and decay rates?

Answer 28

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

Question 29

How many items can be held in short-term memory?

Answer 29

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)

Question 30

In general, what are the details for long-term memory? How does information move to long-term memory?

Answer 30

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

Question 31

What are the forms of long-term memory?

Answer 31

1. **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 2. **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

Question 32

In Long-term Memory, what helps us remember and what can cause us to "forget"

Answer 32

**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 * Do we actually forget, or do we forget have to remember that information?

Question 33

How do you reduce memory load?

Answer 33

Question 34

What is the definition of Cognition?

Answer 34

“of, relating to, being, or involving conscious intellectual activity (as thinking, reasoning, or remembering )”

Question 35

What are the levels cognition occurs on?

Answer 35

**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

Question 36

What are the Conscious and Unconscious details of the following table:

Answer 36

Question 37

How does learning relate to cognition

Answer 37

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

Question 38

What does ballistic and novel mean in the context of leanring?

Answer 38

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

Question 39

What are the implications for design for concious and unconscious cognition?

Answer 39

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

Question 40

What are the processes that transfer information between stores? Sensory -\> short-term Short-term -\> long-term long-term -\> short-term

Answer 40

Sensory -\> short-term: attention Short-term -\> long-term: rehearsal, encoding Long-term -\> short-term: recall