What is a simple definition of [data] visualization?
What are the four main functions of data visualization?
When was the first mouse patented--and by whom?
Why is visualization important?
What's another reason visualization is important?
What did Hal Varian, Google's Chief Economist say about data in the McKinsey Quarterly, Jan. 2009?
What are some of the human challenges with absorbing all the data that's available?
What are some of the benefits of visualization?
Helps us think; uses perception to offload cognition; converts static data into useful information; serves as an external aid (e.g. when we record and store) to augment working memory; allows us to see vast amounts of information within our limited field of view; accelerates search and cognition; boosts our cognitive abilities.
What quotation is attributed to Stuart Card about visulizations?
How close should text that is related to images be placed?
How much attentional capacity do humans normally have?
Explain how our brains have become optimized to have "random access" only when needed:
The brain, like all biological systems, has become optimized over millennia of evolution. Brains have a very high level of energy consumption and must
be kept as small as possible, or our heads would topple us over. Keeping a copy of the world in our brains would be a huge waste of cognitive resources and completely unnecessary. It is much more efficient to have rapid access to the actual world—to see only what we attend to and only attend to what we need—for the task at hand.
How conscious are we about the entire world around us?
Very little. Seeing is all about attention. This new understanding leads to a revision of our thinking about the nature of visual consciousness. It is more accurate to say that we are conscious of the field of information to which we have rapid access rather than that we are immediately conscious of the world.
Define visual thinking:
Give some examples of visual queries:
Where in our visual field is vision focused for detail?
Why do we have to move our eyes to process the world around us?
The non-uniformity of the visual processing power is such that half our visual brain power is directed to processing less than 5 percent of the visual world. This is why we have to move our eyes; it is the only way we can get all that brain power directed where it will be most useful. Non-uniformity is also one of the key pieces of evidence showing that we do not comprehend the world all at once. We cannot possibly grasp it all at once since our nervous systems only process details in a tiny location at any one instant.
What is saccadic eye movement?
Explain why we have a blind spot in our vision:
Explain bottom-up vs. top-down visual processing:
In third-stage visual processing (after a particular "rough" pattern has been identified in the second stage) how many visual objects does our "visual working memory" hold at any one time.
Why does it make very good sense to closely couple order entry with a bar chart with technicals that is the basis for placing an order?
Because visual working memory only holds about three objects which can be displaced by a more task-relevant action. This illustration shows how the binding of concepts that are "activated" (such as seeing a trading signal) and knowledge occurs. Th is momentary binding together of visual information with nonvisual concepts and action priming is central to what it means to perceive something.
Elaborate on our limited capacity of visual working memory and why we can only make due with three or four visual objects at a time:
The reason why we can make do with only three or four objects extracted from the blooming buzzing confusion of the world is that these few objects are made up of exactly what we need to help us perform the task of the moment. Each is a temporary nexus of meaning and action. Sometimes nexus objects are held in mind for a second or two; sometimes they only last for a tenth of a second. Th e greatly limited capacity of visual working memory is a major bottleneck in cognition, and it is the reason why we must often rely on external visual aids in the process of visual thinking.
When we see a pattern, such as a path to exit a room, a "response pattern" (action) is triggered. How can response patterns get traders into trouble?
Is "attention" a bottom-up or top-down visual process?
Why does top-down attention cause a "bias" and can be troublesome for technical traders?
If we are looking for red spots then the red spot detectors will signal louder. If we are looking for slanted lines then slanted line feature detectors will have their signal enhanced. This biasing in favor of what we are seeking or anticipating occurs at every stage of processing. What we end up actually perceiving is the result of information about the world strongly biased according to what we are attempting to accomplish.
Related to visual queries, what is the goal of information design?
With respect to visual thinking, which is easier? Remembering a cognitive operation or re-doing it? (For example, trying to decide between two routes of a subway map to get to a particular destination.)
When looking for something, e.g., a point in a map, when the eye arrives at a point of fixation how fast are patterns evaluated?
When the eye arrives at a point of fixation, a process of visual testing begins, and patterns within the central region of the visual field are evaluated at a rate of about twenty per second; although since the eye only stays in one place for less than two-tenths of a second, roughly one to four simple patterns may be evaluated on each fixation.
Why are data visualizations useful?
Why are visualizations "generally" more useful than text?
Although it does have nice graphic design, it generally fails as an effective data visualization because: (1) It doesn't quickly communicate; (2) it forces the user to use cognitive rather than visual; (3) the 35% is incorrectly scaled and distorts the data. Good data visualizations have more to do with data integrity than "cool" design from the graphics world realm.
According to Edward Tufte, what is design excellence?
(1) The scales are distorted; (2) The design "invites" you to almost compare them equally; (3) the superimposed picture doesn't add anything to making the data understandable--it's almost a gimmick; (4) scales for bar graphs should always start at zero: If -$11,000 is where it's shown, then the bottom of the graph in this perspective is actually at -$4,200,000.
What is the "lie factor" that Edward Tufte refers to?
What are Edward Tufte's three principles of data visualization integrity?
1. Clear, detailed, and thorough labeling should be used to defeat graphical distortion and ambiguity.
2. The representation of numbers, as physically measured on the surface of the graphic itself, should be directly proportional to the numerical quantities represented.
3. Most important: Show data variation, not design variation.
Compare pie charts vs. bar charts:
Pie charts measure the composition and components of set of data--and are "flashier"; bar charts rank the components in a clear, relative fashion and often communicate with more integrity. Because of this, bar charts are easier to process visually. The goal is to take advantage of the visual system so that the data pops out.
We want to maximize the ratio of data to ink being used. This graphic is still difficult to interpret. There is a lot of wasted ink in using 3D and creating drop shadows. Is it more compelling than than a 2D bar chart? Yes. Is it more communicative? No. The rule is: Use as little ink as possible to show the data.
Should chart junk NEVER be used? Are there cases where chartjunk serves one or more purposes? Explain.
What does Tufte mean by saying 'increase data density'?
What are spark lines? Who invented them.
What are Edward Tufte's four design principles?
Is chartjunk always harmful?
What are the basic rules for creating graphs?
(1) Present all the data that is needed for the audience to see and understand what’s meaningful; (2) present nothing that isn’t needed; (3) rrepresent data accurately; (4) represent data in a way that is easy for the eyes to perceive and the brain to interpret; (5) provide appropriate context for interpreting the meaning of the data.
What are some of the subjective dimensions related to graphical embellishments of visualizations?
What are Robin Williams' (author of Non-designers Design Book) four design principles?
Acronym = CRAP (C.R.A.P.):
1. Contrast--if two things are different, make them REALLY different (don't be a wimp)
2. Repetition--Repeat some aspects of the design throughout the entire piece (e.g., where/how bullets, headings, bold, italics, indents, etc. are used)
3. Alignment--Nothing should be placed on the page arbitrarily. Every item should have a visual connection with something else
4. Proximity--Group related items together... as
physical closeness implies a relationship.
1. Data/ink ratio is low: too much saturated and bright (loud) distracting color and unnecessary graphics; contrast is very high--yet two of the purples are similar
2. Chart junk: the spiral takes some time to figure out, even though it does draw the eye into the design; it probably distorts the data, as well.
3. Data density is on the low side
4. Little information is layered here other than the high contrast with colors
5. The fonts seem mixed and not a good choice.
The graphic above is an improvement based on Tufte's design principles.
What is Edward Tufte's quotation re clutter in design?
Name the three "intended tasks" of data visualization according to Tamara Munzner:
According to Tamara Munzner, what are the limitations when analyzing a visualization system?
What is "change blindness" ?
What are some of the things IDEO does in their design process?
In design, what are the steps in the "Design Flow" process?
Explain the Empathize step in the Understand Domain phase of Design Flow:
Explain the Define step in the Task Abstraction phase of Design Flow:
Explain the Ideate step in the Visual Encodings phase of Design Flow:
Explain the Prototype step in the Build Visualization phase of Design Flow:
Explain the Test step in the Evaluation phase of Design Flow:
Review the IDEO's Design Flow model which, in the end, is a visualization:
Step 1 is the "target": What is the problem to work on? Lean about users' goals and kinds of data--then get and clean data. Then you need to "translate" that data to structure and characterize the data from which you create an abstraction of the problem--and from there, transform the data computationally. Only once you've done this can you go into the design phase. Then comes implementation. Lastly is validation.
What is "affinity diagramming" ?
It's the "sticky note" concept to group data... More formally, it's a group decision-making technique designed to sort a large number of ideas, process variables, concepts, and opinions into naturally related groups. These groups are connected by a simple concept. These ideas can be posted on Post-it note pads for eventual grouping, sorting, pattern finding, etc.
With respect to perception, what are some of the differences between our eyes and a camera?
(1) Our eyes are task directed; (2) cameras have evenly distributed pixels whereas our eyes pixel focus is concentrated; (3) we have a brain which does visual processing in a hierarchical manner ; (4) in the brain, we get what we focus on, e.g., finding a red dot; (5) the brain is both bottom-up and top-down.
Explain the difference between bottom-up and top-down processing:
In bottom-up, the brain processes what we see up into the brain into cognition. We see low-level features which get processed in the brain as, "That's a dog..."
In top-down, the process starts from cognition in the brain down in HOW we see things. Optical illusions are top-down: The brain is wired a certain way and creates an illusion that something is appearing a certain way--when it is not.
Explain the hierarchical nature of bottom-up and top-down visual processing:
Both happens simultaneously. In bottom-up, information drives pattern building: An image comes in through the eye then patterns or shapes emerge then they are converted to "objects" in our mind from which we form ideas, opinions, actions, etc. Top-down attentional process reinforce relevant information, i.e., in a very simple sense, we get what we are looking for. So when SEEING a dog, that information gets processed bottom up--and when we look back at the dog, the information about the dog becomes clearer (top-down).
What is very important with respect to bottom-up and top-down visual processing as it relates to data visualization?
Name a common problem with design and visualizations today:
Name Dieter Rams' ten principles of "good design"
Regarding "data encoding," comment on how to display continuous data vs. discrete data in charts:
What is a bumps chart?
In bar charts, which is better to use? 2-D or 3-D?
Graphically, which is easier to compare: line charts or line charts that are filled in, taking advantage of the negative space?
In Design Flow process, what is the ratio of time spent between the target and translation phases vs. the design and implementation phases?
What is the waterfall model of design?
The waterfall model is a popular version of the systems development life cycle model for software engineering. Often considered the classic approach to the systems development life cycle, the waterfall model describes a development method that is linear and sequential. Waterfall development has distinct goals for each phase of development.
Disadvantage: It constrains users from going back to prior steps in the process. Designers are moving away from it into agile development and other methods.
Explain the agile development model:
Agile software development is a group of software development methods based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams. It promotes adaptive planning, evolutionary development and delivery, a time-boxed iterative approach, and encourages rapid and flexible response to change. It is a conceptual framework that promotes foreseen interactions throughout the development cycle.
What is Mechanical Turk as it pertains to data visualization?
It is crowdsourcing service (hosted by Amazon) that pays people to do various computer tasks. For example designers can visually test their models by paying small amounts to crowdsourced users to perform evaluations. On the receiving end, it lets people earn money for doing small computer tasks like eyeballing and commenting on photos, answering questions about websites, etc.
Give examples of the taxonomy of data:
What is the difference between Data Models vs. Conceptual Models
What is the formal definition of measurement?
Elaborate on the four Data Types:
What are the operators on the four data types?
What is the process of going from data model to data type?
(1) We consider the data coming in; (2) from that we derive a conceptual model, for example, temperature; (3) and from that we decide on the data type. For example, if measuring temperature do we need to round to four figures (quantitative); or do we consider the temperature is either hot, warm, or cold (ordered); or do we take a more binary approach and say that the toast is either burned or not burned (nominal).
Name some places where texture should not be used:
What is the Principal of Consistency?
What is the Principle of Importance Ordering?
With respect to visual queries, what is the mechanism known as biased competition?
Is the mechanism in our brains that when we go for example searching for tomatoes, it's as if the brain is saying, "All of you read sensitive cells you all have permission to shout louder. All you blue– and green–sensitive cells, try to be quiet." The same biased shouting mechanism also applies to any of the feature types processed by the primary visual cortex, including orientation, size, and motion.
During visual queries, which features lead to a pop out (salience)?
How long this processing take to determine if an object pops out from its surroundings? Why is this important for data visualizations?
Something that pops out can be seen in a single eye fixation and experiments show that processing to separate a pop-out object from its surroundings actually takes less than a tenth of a second. Things that do not pop out require several eye movements to find, with eye movements taking place at a rate of roughly three per second. Between one and a few seconds may be needed for a search. These may seem like small differences, but they represent the difference between visually efficient at-a-glance processing and cognitively effortful search.
Trying to find the target a son to features is called a visual conjunctive search, and most visual conjunctions are hard to see. The green squares do not show a pop-out effect, even though you know what to look for. The problem is that your primary visual cortex can either be tuned for the square shapes, or the green things, but not both.
Are features that pop out hard wired into the brain--or can we learn to spot them through practice?
Features that do pop out are hardwired into the brain. As it relates to trading, for example, with practice experts can interpret patterns that non-experts fail to see. But this expertise applies more to identifying patterns once they have been fixated with the eyes, and not to finding those patterns out of the corner of the eye .
Given how our brains are hardwired, how do we support visual queries in design when we need more than one element to stand out?
A design to support a rapid visual query for two different kinds of symbols from among many others will be most effective if each kind of query uses a different channel. We can use shape coding for one and color coding for the other, for example. Also, we can hierarchically subordinate one element to another by adding, let's say, three channels to one element and to channels to the other, thereby making them both pop but one more than the other.
At an evolutionary level, where does our sensitivity to motion come from?
It likely comes from our need for safety when our surroundings change, for example, movement in the brush in the Savannah will help us from becoming some creature's lunch. Our sensitivity to static detail. Very rapidly away from the central fovea. Our sensitivity to motion. Much less, so we can still see something is moving out of the corner of our eye, even though the shape is invisible.
How can the foregoing concepts improve on the "text-on-charts" application?
By converting the text to a uniform decision making structure using visual queues. Your Decision Bars was a step in this direction. All indicators could conceivably be pumped into the decision bar format which could either be displayed at the bottom of the chart on a bar-by-bar basis--or in a right hand margin of symbols from which the trader can act on from a top-down cognitive basis.
Rather than place buy-sell arrows above areas on charts, how can the signal generation process be enhanced on charts?
What helps the brain find an object and distinguish it from others in the environment?
Finding the boundaries of an object is an important function of the pattern processing systems. In order for the brain to find an object, it must somehow be distinguished from other objects in the environment, and often the most important piece of information is that it has a continuous contour running all around it. In the trading realm, that means the current bar you are looking at is almost indistinguishable from others nearby and it takes comparatively more cognitive energy to resolve what you are seeing.
What is binding as it relates to visual processing?
The process of combining different features that will come to the identified as parts of the same contour or region is called binding. There is no such thing as an object embedded in an image; purchase patterns of light, shape, color, and motion. Objects and patterns must be discovered, and binding is essential because it is what makes disconnected pieces of information into connected pieces of information.
What is visual interference?
What is feature level tuning?
By way of analogy, what's the difference between small-scale patterns and large-scale patterns?
Objects in the real world have structure at many scales. In the garden, for example, individual flowers provide small-scale patterns, and these are organized into patches of color depending on the design of a flower bed. The entire structure of lawns, flowerbeds, trees, and pass form a large-scale pattern.
Give some examples of how relationships between meaningful graphical entities can be established: