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  • 1. © 2009 Stephen Few, Perceptual Edge 1 It is not enough to mine the meanings that exist in your data. The value of information is not realized until you use it to do something. Used properly, it can make the world a better place.
  • 2. © 2009 Stephen Few, Perceptual Edge 2 This poem by Edna St. Vincent Millay eloquently and poignantly describes our situation today. Our problem is not a lack of data, but rather our inability to make sense and use of what we have.
  • 3. © 2009 Stephen Few, Perceptual Edge 3 The amount of information that is available to us has grown much faster than our ability to make use of it. We lack both skills in data analysis and tools that can be used to productively support the process.
  • 4. © 2009 Stephen Few, Perceptual Edge 4 According to Richards J. Heuer, Jr.: Once an experienced analyst has the minimum information necessary to make an informed judgment, obtaining additional information generally does not improve the accuracy of his or her estimates. (Psychology of Intelligence Analysis, 1999)
  • 5. © 2009 Stephen Few, Perceptual Edge 5 Most of the data analysis that is needed in the normal course of business requires relatively simple data visualization techniques, leaving little that requires the sophisticated techniques of statistical and financial analysis.
  • 6. 6 If you search for resources that teach data analysis skills, you’ll find many books and courses that present the sophisticated techniques needed by the few, but few resources if any that teach the simple techniques that most of us need to make sense of business data. The skills that most of us need to infuse our businesses with needed insights can be learned without a background in statistics, but these skills don’t come naturally – they must be learned. You must develop expertise, but it is expertise that can be easily learned with the proper direction and practice. You must learn to see particular patterns in data that are meaningful. People can learn pattern-detection skills, although the ease of gaining these skills will depend on the specific nature of the patterns involved. Experts do indeed have special expertise. The radiologist interpreting an X-ray, the meteorologist interpreting radar, and the statistician interpreting a scatter plot will each bring a differently tuned visual system to bear on his or her particular problem. People who work with visualizations must learn the skill of seeing patterns in data. (Information Visualization: Perception for Design, Second Edition, Colin Ware, Morgan Kaufmann Publishers, 2004, page 209) © 2009 Stephen Few, Perceptual Edge
  • 7. 7© 2009 Stephen Few, Perceptual Edge Good tools, from stones for crushing or cutting to computers for augmenting cognition, can set us free and make the world a better place, but only when used properly. When misused, they make us lazy, dumb, slaves. The choice is ours.
  • 8. © 2009 Stephen Few, Perceptual Edge 8 To date, business intelligence has mostly focused on technology and project methodology, resulting in great advances. As a result, we have huge and fast warehouses of information. It is now time to focus on the true essence of business intelligence—important, meaningful, and actionable information—and the most powerful resources for tapping into its value are those that engage the tremendous capacities of human perception and intelligence to make sense of and communicate information. Many organizations aren't effectively analyzing the data they do have to improve their business. What's more troubling, perhaps, is many companies that purchase powerful analysis and business-intelligence tools don't use them effectively. Users of these products often generate the most basic and obvious reports and never get their hands dirty with the deep-analysis tools. By ignoring these products' deep-analysis capabilities, organizations could be missing important trends—information that might show, for example, where a company is losing business. Companies might also see that business decisions that were made based on basic information were wrong and ended up costing money in the long run. (eWeek, ―With Data Analysis, Less Isn’t More, Jim Rapoza, Ziff Davis Media Incorporated, June 7, 2004) Today much of science and engineering takes a machine-centered view of the design of machines and, for that matter, the understanding of people. As a result, the technology that is intended to aid human cognition and enjoyment more often interferes and confuses than aids and clarifies. It will take extra effort do design systems that complement human processing needs. It will not always be easy, but it can be done. If people insisted, it would be done. But people don’t insist: Somehow, we have learned to accept the machine-dominated world. If a system is to accommodate human needs, it has to be designed by people who are sensitive to and understand human needs. I would have hoped such a statement was an unnecessary truism. Alas, it is not. (Things That Make Us Smart, Donald A. Norman, Basic Books, New York, 1993, page s 9 and 227)
  • 9. © 2009 Stephen Few, Perceptual Edge 9 Data visualization has the potential to help business intelligence fulfill its promise of helping organizations function intelligently.
  • 10. © 2009 Stephen Few, Perceptual Edge 10 Data visualization is the loom that will weave the data that we collect into the fabric of understanding. Pictures of data can make visible the meanings that might forever otherwise remain hidden.
  • 11. © 2009 Stephen Few, Perceptual Edge 11 Though data visualization has become a popular tool of business intelligence only recently, people have been using graphs to display data visually for a long time. In 1786, a roguish Scot—William Playfair—published a small atlas that introduced or greatly improved most of the quantitative graphs that we use today. Prior to this, graphs of quantitative data were little known.
  • 12. © 2009 Stephen Few, Perceptual Edge 12 Today, 220 years later, graphs are commonplace, fully integrated into the fabric of modern communication. Surprisingly, however, Playfair’s innovative efforts— spring from meager precedent—are superior to most of the graphs produced today.
  • 13. © 2009 Stephen Few, Perceptual Edge 13
  • 14. © 2009 Stephen Few, Perceptual Edge 14 Hans Rosling of Gapminder.org has become one of the real stars of information visualization in the last couple of years. When Rosling took the stage at the TED conference for the first time in 2006, he managed to get people up on the edges of their seats to watch—believe it or not—a bubble plot that used animation (motion) to show change through time. When he finished, the crowd rose to their feet to give Rosling a standing ovation. For most of the people there, data presentation had never been so compelling. Rosling has used relatively simple visualization techniques, featuring animated plots, to tell statistical stories that are compelling, not only because they are told with great charisma, but because they reveal important truths about the world, such as the changing relationship between wealth and child mortality. I applaud his success, in part because it is success that we can share in, for it illustrates to the world at large what infovis can do when it is done well and it is used for worthwhile purposes.
  • 15. © 2009 Stephen Few, Perceptual Edge 15 When Al Gore rode a scissor crane up to the top of the CO2 emissions graph in the film An Inconvenient Truth, he became a superstar of visual communications. He compellingly used graphs to tell the story of global warming, which helped public opinion in America to finally reach the tipping point.
  • 16. 16 Data visualization begins with (1) searching through the data to discover potentially meaningful facts, then involves (2) examining that data more closely to understand it, including what caused it to occur, so that you can then (3) explain what you’ve learned to those who can use that knowledge to make good decisions. Most of what we need to recognize and understand in our business data is not all that complicated. © 2009 Stephen Few, Perceptual Edge
  • 17. 17 Human perception is amazing. I cherish all five of the senses that connect us to the world, that allow us to experience beauty and an inexhaustible and diverse wealth of sensation. But of all the senses, one stands out dramatically as our primary and most powerful channel of input from the world around us, and that is vision. Approximately 70% of the body’s sense receptors reside in the eye. Perhaps the world’s top expert in visual perception and how its power can be harnessed for the effective display of information is Colin Ware, who has convincingly described the importance of data visualization. He asks: Why should we be interested in visualization? Because the human visual system is a pattern seeker of enormous power and subtlety. The eye and the visual cortex of the brain form a massively parallel processor that provides the highest-bandwidth channel into human cognitive centers. At higher levels of processing, perception and cognition are closely interrelated, which is the reason why the words ‘understanding’ and ‘seeing’ are synonymous. However, the visual system has its own rules. We can easily see patterns presented in certain ways, but if they are presented in other ways, they become invisible…The more general point is that when data is presented in certain ways, the patterns can be readily perceived. If we can understand how perception works, our knowledge can be translated into rules for displaying information. Following perception-based rules, we can present our data in such a way that the important and informative patterns stand out. If we disobey the rules, our data will be incomprehensible or misleading. (Information Visualization: Perception for Design, Second Edition, Colin Ware, Morgan Kaufmann Publishers, 2004, page xxi) Perhaps the best known expert in data visualization, Edward Tufte, says: ―Clear and precise seeing becomes as one with clear and precise thinking.‖ (Visual Explanations, Edward R. Tufte, Graphics Press: Cheshire, CT.1997 page 53) © 2009 Stephen Few, Perceptual Edge
  • 18. 18 The presentation of data as text, such as you see in this table, is perfect when you need precise values or when the purpose is to look up or compare individual values, but not when you wish to see patterns, trends, and exceptions, or to make comparisons. When this is your goal, visualizations work best. When data is presented visually, it is given visible form, and from this we can easily glean insights that would take a long time to piece together from the same data presented textually, if ever. This graph of the same data that appears in the table makes brings to light several of the stories contained in the data that weren’t obvious before, and it did so instantly. When] we visualize the data effectively and suddenly, there is what Joseph Berkson called ‘interocular traumatic impact’: a conclusion that hits us between the eyes. (Visualizing Data, William S. Cleveland, Hobart Press, 1993, page 12) Modern data graphics can do much more than simply substitute for small statistical tables. At their best, graphics are instruments for reasoning about quantitative information. Often the most effective way to describe, explore, and summarize a set of numbers – even a very large set – is to look at pictures of those numbers. Furthermore, of all methods for analyzing and communicating statistical information, well-designed data graphics are usually the simplest and at the same time the most powerful. (The Visual Display of Quantitative Information, Edward R. Tufte, Graphics Press: Cheshire, CT 1983, Introduction) © 2009 Stephen Few, Perceptual Edge
  • 19. © 2009 Stephen Few, Perceptual Edge 19 So much of what is called ―data visualization‖ gives it a bad name and causes confusion about what it is, how it works, and what can be accomplished when it is properly done.
  • 20. © 2009 Stephen Few, Perceptual Edge 20 Software vendors are competing to out dazzle one another with silly visual effects that treat data visualization like it’s a video game.
  • 21. © 2009 Stephen Few, Perceptual Edge 21 This notion of data visualization is not about understanding and communication, it’s about bling.
  • 22. © 2009 Stephen Few, Perceptual Edge 22 Dashboards are notorious for featuring graphical glitz over substance. Too many dashboard vendors and designers have lost sight of the bottom line: communication. They emphasize graphical glitz over clear and meaningful content. For every item of information on the screen the designer should ask the question: ―How can I display this information in the most meaningful, clear, and efficient way possible?‖ The graphics in this dashboard from Business Objects, created with Xcelsius, are beautifully rendered, but is the information effectively displayed? The Xcelsius team clearly possesses exceptionable graphical skill. This isn’t surprising, given the fact that most of the original team of developers formerly developed video games. Unfortunately, they failed to make the transition from video games to data visualization.
  • 23. 23 Data visualization essentially helps us to do two things: (1) think about information more effectively so we can understand it means, and then (2) tell its story clearly and accurately to others. © 2009 Stephen Few, Perceptual Edge
  • 24. © 2009 Stephen Few, Perceptual Edge 24 My first two books addressed the communication aspects of data visualization.
  • 25. © 2009 Stephen Few, Perceptual Edge 25 Data visualization is much more than just graphical reporting, more than dashboards. Beyond its use for communicating information that cannot be communicated with tabular data, its greatest potential is exhibited in its use for analysis. The best techniques for making sense of business data are visual techniques, which extend our ability to find and understand meaningful patterns in data by offloading much of the work traditionally performed by the conscious mind to preconscious and parallel processors in the brain’s visual cortex. Most BI vendors provide some graphical functionality in their software, but few actually support visual analysis in more than rudimentary ways.
  • 26. © 2009 Stephen Few, Perceptual Edge 26 During the last year I wrote a new book, Now You See It, to help people develop the fundamental skills that are needed to make sense of quantitative information.
  • 27. 27 Visual analysis involves comparing the magnitudes of values, but not just one to another. We must compare many values. To do so, we must see how they relate to one another to form patterns. We not only compare the magnitudes of values; we also compare patterns formed by sets of values. We look for how they are similar and we look for how they are different, especially differences that appear to be dramatic departures from the norm. When we spot these visual characteristics in the data, we then interact with the data to find out why these things have happened. © 2009 Stephen Few, Perceptual Edge
  • 28. 28© 2009 Stephen Few, Perceptual Edge
  • 29. © 2009 Stephen Few, Perceptual Edge 29 Many of the ways that visual perception work are not intuitive. Looking at these two sets of objects, we naturally see those on the left as convex and on those the right as concave.
  • 30. © 2009 Stephen Few, Perceptual Edge 30 The effect has now been reversed: we see the objects on the left as concave and those on the right as convex. All I did, however, was turn each sets of objects upside down—I didn’t switch them. The reason that we now see those on the left as concave is because, through eons of evolution, visual perception learned to assume that light was shining from above, which causes us to see the objects on the left as concave, because the shadows are on the top, and those on the right as convex, because the shadows are on the bottom.
  • 31. 31© 2009 Stephen Few, Perceptual Edge
  • 32. 32 Despite how differently they look in the original image, squares A and B are exactly the same color. What we see is not a simple recording of what is actually out there. Seeing is an active process that involves interpretations by our brains of data that is sensed by our eyes in an effort to make sense of it in context. The presence of the cylinder and its shadow in the image of the checkerboard triggers an adjustment in our minds to perceive the square labeled B as lighter than it actually is. The illusion is also created by the fact that the sensors in our eyes do not register actual color but rather the difference in color between something and what’s nearby. The contrast between square A and the light squares that surround it and square B and the dark squares that surround it cause us to perceive squares A and B quite differently, even though they are actually the same color, as you can clearly see above after all of the surrounding context has been removed. The ability to use graphs effectively requires a basic understanding of how we unconsciously interpret what we see. © 2009 Stephen Few, Perceptual Edge
  • 33. 33 This image illustrates the surprising effect that a simple change in the lightness of the background alone has on our perception of color. The large rectangle displays a simple color gradient of a gray-scale from fully light to fully dark. The small rectangle is the same exact color everywhere it appears, but it doesn’t look that way because our brains perceive visual differences rather than absolute values, in this case between the color of the small rectangle and the color that immediately surrounds it. Among other things, understanding this should tell us that using a color gradient as the background of a graph should be avoided. © 2009 Stephen Few, Perceptual Edge
  • 34. 34 There is a distinct image that has been worked into the picture of the rose, which isn’t noticeable unless we know to look for it. Once primed with the image of the dolphin, however, we can easily spot it in the rose. Data visualizations must encode meaningful information as patterns that we can learn to spot and understand. (Note: The image of the rose was found at www.coolbubble.com.) © 2009 Stephen Few, Perceptual Edge
  • 35. 35 From this set of six playing cards, select one and remember it. I will now identify and remove the card that you’ve selected, then rearrange those that remain. As I advance to the next slide, you’ll discover that your card has been eliminated. © 2009 Stephen Few, Perceptual Edge
  • 36. 36 Amazing. And I can do this again and again. If you go back to the previous slide and again pick a card, when you return to this slide you will see that I’ve once again eliminated it. Actually, as I’m sure you realize, this card trick is an illusion that makes use of the limitations of short-term memory. None of the cards on the second screen are the same as the cards on the first screen, but you probably didn’t notice this because you only remembered the card that you selected, not the others. © 2009 Stephen Few, Perceptual Edge
  • 37. 37 In addition to understanding visual perception, visual analysis tools must also be rooted in an understanding of how people think. Only then can they recognize and support the cognitive operations that are necessary to make sense of information. Memory plays an important role in human cognition. Because memory suffers from certain limitations, visual analysis tools must be able to augment memory. The example above illustrates one of the limitations of working memory. We only remember that to which we attend. Any part of this image that never gets our attention will not be missed when we shift to another version of the image that lacks that particular part. If we don’t attend to it, we might notice the change from one version of the image to the next, but only if the transition shift immediately from one to another, without even a split second of blank space between them. In addition to not remembering, we also don’t clearly see that on which we don’t focus. To see something clearly, we must focus on it, for only a small area of receptors on the retinas of our eyes are designed for high-resolution vision. (Source: This demonstration of change blindness was prepared by Ronald A. Rensink of the University of British Columbia. Several other examples of this visual phenomenon can be found at http://www.psych.ubc.ca/%7erensink/flicker/download/index.html.) © 2009 Stephen Few, Perceptual Edge
  • 38. © 2009 Stephen Few, Perceptual Edge 38 When we think about things, trying to make sense of them, the place where information is temporarily stored to support this process is called working memory. Working memory is a lot like RAM (random access memory) in a computer in that it is limited in capacity and designed for temporary storage. Compared to that hard disk drive, which is built into your computer or attached to it externally, RAM seems very limited, but compared to working memory in the human brain, RAM seems enormous. Only around three chunks of visual information can be stored in working memory at any one time. Information that comes in through our eyes or that is retrieved from long-term memory in the moment of thought is extremely limited in capacity. If all four storage slots are occupied, you must let something go to allow something new to come in. When you release information from working memory, it can take one of two possible routes on its way out: 1) it can be stored permanently in long-term memory by means of a rehearsal process that we call memorization, or 2) it can simply be forgotten.
  • 39. © 2009 Stephen Few, Perceptual Edge 39 To compare facts, you must hold them in working memory simultaneously. Because we can hold so little in working memory at any one time, however, to do analysis effectively, we must rely on external aids to memory. This is an ideal job for a computer. Even a piece of paper that you jot down notes on to keep track of information as you’re analyzing data is an external memory aid that is quite powerful despite being low-tech. A computer running properly designed software, however, can augment our ability to think about information much better than pencil and paper.
  • 40. © 2009 Stephen Few, Perceptual Edge 40 Good visual analysis software can help us overcome the limitations of working memory in several ways. The goal is to enable as many meaningful comparisons as possible. Good tools can help us increase: • The amount of information that we can compare (that is, greater quantity) • The range of information that we can compare (that is, more dimensions) • The different views of the information that we can compare (that is, multiple perspectives)
  • 41. © 2009 Stephen Few, Perceptual Edge 41 Traditional BI relies mostly on tabular data displays. Tables are wonderful if you need to look up individual values, compare a single value to another, or know values precisely, but they don’t display patterns or trends. This is a problem, because data analysis relies heavily on our ability to spot and make sense of patterns and trends in data. Take a look at the table and compare it to this line graph, which displays the same data. Relying on the table to discern the ups and downs of sales through time and to compare the patterns of change from region to region would yield very little of the information that is obvious in this graph. Visual representations give form to data, making pattern, trends, and exceptions easy to see. Another advantage of properly designed graphs over tables for analytical purposes is less obvious. If you needed to remember information in the table, you could hold only about four of the values (that is, four of the monthly sales numbers) in working memory at any one time. But by relying on the graph, 12 values are combined into each of the four lines to form a pattern that you could hold entirely as a single chunk in working memory. Simply by giving visual form to the values, you can hold much more information in memory.
  • 42. © 2009 Stephen Few, Perceptual Edge 42 You can extend the benefits of data visualization further by arranging several graphs on the screen at the same time, such as shown in this visual crosstab. Here you can see 24 small graphs arranged in familiar crosstab fashion to present sales across four different dimensions at once: products within product types by row, regions by column, and market size by the color of the line. Not only does this approach make a great deal of data available to your eyes, it does so across several dimensions, thus expanding the dimensionality of the data well beyond traditional graphical displays.
  • 43. © 2009 Stephen Few, Perceptual Edge 43 To understand something, we often have to examine it from many angles and focus on many parts. Too much business data analysis involves looking only for one thing in particular. Is revenue going up? The answer is ―yes‖ or ―no‖—end of story. Perhaps, however, you ought to look at revenues, expenses, profits, marketing campaigns, seasonality, composition of the sales force, new product introductions, and the competition to understand the richer story that your data has to tell.
  • 44. © 2009 Stephen Few, Perceptual Edge 44 There’s an old folktale that you’ve probably all heard about three blind men who encounter an elephant one day for the first time and do their best to learn about it by touch alone. The experience of each is unique because each touches a different part of the elephant. This ancient story, originally from China, can teach us something important today about business intelligence (BI). According to the original Chinese tale, the first man touches the elephant’s ear, the second his legs, and the third his tail. From this point, here’s how the story goes: The three blind men then went their way. Each one was secretly excited over the experience and had a lot to say, yet all walked rapidly without saying a word. "Let's sit down and have a discussion about this queer animal," the second blind man said, breaking the silence. "A very good idea. Very good." the other two agreed for they also had this in mind. Without waiting for anyone to be properly seated, the second one blurted out, "This queer animal is like our straw fans swinging back and forth to give us a breeze. However, it's not so big or well made. The main portion is rather wispy." "No, no!" the first blind man shouted in disagreement. "This queer animal resembles two big trees without any branches." "You're both wrong." the third man replied. "This queer animal is similar to a snake; it's long and round, and very strong." How they argued! Each one insisted that he alone was correct. Of course, there was no conclusion for not one had thoroughly examined the whole elephant. How can anyone describe the whole until he has learned the total of the parts. If I retold this story today to teach a lesson about BI, I might call it ―Three blind analysts and a data warehouse.‖ Business people struggle every day to make sense of data, stumbling blindly, touching only small parts of the information, and coming away with a narrow and fragmented understanding of what it means.
  • 45. © 2009 Stephen Few, Perceptual Edge 45 The tabular model forces us to view small slices of information one piece at a time, which cannot possibly be stitched together in our brains to tell the whole story.
  • 46. 46 The process of visual data analysis involves several common interactions with data to uncover what’s meaningful. Here are some of the primary interactions: • Sorting. The act of sorting data, especially by the magnitude of the values from high to low or low to high, features the ranking relationship between those values and makes it easier to compare the magnitude of value to the next. • Adding/removing variables. You might need to view different variable at different times during the analysis process, so it is common to add or remove field of data from view as necessary • Filtering. When you want to focus on a subset of data, nothing makes it easier to do so than filtering—the removal from view of everything your not interested in at the moment. • Highlighting. Sometimes you want to focus on a subset of information, but do so in a way that allows you to maintain a sense of how that subset relates to the whole. Rather than filtering out the data that falls outside your range of focus, you can simply reduce its visual salience or increase the visual salience of the data you wish to focus on. This allows you to focus on the subset with less distraction from the whole in a way that allow you to remain aware of the whole. This is one way of achieving what’s called a focus+context view. • Aggregating/Disaggregating. Analysis often requires that you examine data a different levels of detail. Aggregation involves viewing data at a higher level of summarization. Disaggregation involves viewing data at a lower level of detail. • Drilling. Similar to disaggregation, drilling involves viewing data at a lower level of detail, but in a specific manner. Drilling also means that you are changing the view to the next level in a defined hierarchy, and excluding from view all data that is not directly related to the specific data value that you chose to drill into. For instance, if you drill into a particular product family, your next view only products that belong to that product family. In other words, a form of filtering is involved. • Grouping. Sometimes it is useful to combine members of a variable together, treating them as a single member of the variable. This may take the form of combining some members and leaving others as they are, or of creating an entirely new variable that combines all members of an existing variable into a groups to form members of a higher level variable. • Zooming/Panning. When a data visualization contains so much that it is difficult to clearly see all the data at once, it is useful to zoom in on that portion that you want to see more clearly. Panning involves moving around (for example, up, down, right, or left) in a zoomed view to focus on a different part of the larger visualization. • Re-visualizing. No one visual representation of data can show you everything there is to see, so visual analysis involves shifting from one type of visualization to another to explore data from various perspectives. • Re-expressing. Sometimes it is useful to express a quantitative variable as a different unit of measure, such as expressing dollars as percentages. • Re-scaling. No single quantitative scale on a graph can serve every analytical need. Rescaling involves changing the range of the quantitative scale to make it easier to see particular patterns and sometimes even changing the nature of the scale, such as from a normal scale to a logarithmic scale. © 2009 Stephen Few, Perceptual Edge
  • 47. © 2009 Stephen Few, Perceptual Edge 47 Direct dynamic interaction with the properly visualized data allows us to see discover meaningful patterns, trends, and exceptions in the display and to interact with it directly to filter out what we don’t need, drill into details, combine multiple variables for comparison, etc., in ways that promote a smooth flow between seeing something, thinking about it, and manipulating it, with no distracting lags in between. This is what I call ―visual analysis at the speed of thought.‖
  • 48. © 2009 Stephen Few, Perceptual Edge 48 When new recruits by intelligence organizations are trained in spy craft, they are taught a method of observation that begins by getting an overview of the scene around them while being sensitive to things that appear abnormal, not quite right, which they should then focus in on for close observation and analysis. A visual information-seeking mantra for designers: ‘Overview first, zoom and filter, then details-on-demand.’ (Readings in Information Visualization: Using Vision to Think, Stuart K. Card, Jock D. Mackinlay, and Ben Shneiderman, Academic Press, San Diego, California, 1999, page 625) Having an overview is very important. It reduces search, allows the detection of overall patterns, and aids the user in choosing the next move. A general heuristic of visualization design, therefore, is to start with an overview. But it is also necessary for the user to access details rapidly. One solution is overview + detail: to provide multiple views, an overview for orientation, and a detailed view for further work. (Ibid., page 285) Users often try to make a ‘good’ choice by deciding first what they do not want, i.e. they first try to reduce the data set to a smaller, more manageable size. After some iterations, it is easier to make the final selection(s) from the reduced data set. This iterative refinement or progressive querying of data sets is sometimes known as hierarchical decision-making. (Ibid., page 295)
  • 49. © 2009 Stephen Few, Perceptual Edge 49 Shneiderman’s technique begins with an overview of the data—the big picture. Let your eyes search for particular points of interest in the whole.
  • 50. © 2009 Stephen Few, Perceptual Edge 50 When you see a particular point of interest, then zoom in on it.
  • 51. © 2009 Stephen Few, Perceptual Edge 51 Once you’ve zoomed in on it, you can examine it more closely and in greater detail.
  • 52. © 2009 Stephen Few, Perceptual Edge 52 Often you must remove data that is extraneous to your investigation to better focus on the relevant data.
  • 53. © 2009 Stephen Few, Perceptual Edge 53 Filtering out extraneous data removes distractions from the data under investigation.
  • 54. © 2009 Stephen Few, Perceptual Edge 54 Visual data analysis relies mostly on the shape of the data to provide needed insights, but there are still times when you need to see the details behind the shape of the data. Having a means to easily see the details when you need them, without having them in the way when you don’t works best.
  • 55. © 2009 Stephen Few, Perceptual Edge 55 Information cannot speak for itself. It needs our help. It relies on us to give it a voice. When we do, information can tell its story, and will thus become knowledge. The ultimate goal, however, isn’t knowledge; it is wisdom. Knowledge becomes wisdom when it is used to do something good. Only when we use what we know to make the world a better place has information served its purpose and we have done our job. Our networks are awash in data. A little of it is information. A smidgen of this shows up as knowledge. Combined with ideas, some of that is actually useful. Mix in experience, context, compassion, discipline, humor, tolerance, and humility, and perhaps knowledge becomes wisdom. Turning Numbers into Knowledge, Jonathan G. Koomey, 2001, Analytics Press: Oakland, CA page 5, quoting Clifford Stoll.
  • 56. 56© 2009 Stephen Few, Perceptual Edge O perpetual revolution of configured stars, O perpetual recurrence of determined seasons, O world of spring and autumn, birth and dying! The endless cycle of idea and action, Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of The Word. All our knowledge brings us nearer to our ignorance, All our ignorance brings us nearer to death, But nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? Excerpt from The Rock, 1930, T.S. Elliot [Image source: www.irishastronomy.org]
  • 57. 57© 2009 Stephen Few, Perceptual Edge O perpetual revolution of configured stars, O perpetual recurrence of determined seasons, O world of spring and autumn, birth and dying! The endless cycle of idea and action, Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of The Word. All our knowledge brings us nearer to our ignorance, All our ignorance brings us nearer to death, But nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? Excerpt from The Rock, 1930, T.S. Elliot [Image source: www.trekvisual.com]
  • 58. 58© 2009 Stephen Few, Perceptual Edge O perpetual revolution of configured stars, O perpetual recurrence of determined seasons, O world of spring and autumn, birth and dying! The endless cycle of idea and action, Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of The Word. All our knowledge brings us nearer to our ignorance, All our ignorance brings us nearer to death, But nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? Excerpt from The Rock, 1930, T.S. Elliot [Image source: www.i.pbase.com]
  • 59. 59© 2009 Stephen Few, Perceptual Edge O perpetual revolution of configured stars, O perpetual recurrence of determined seasons, O world of spring and autumn, birth and dying! The endless cycle of idea and action, Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of The Word. All our knowledge brings us nearer to our ignorance, All our ignorance brings us nearer to death, But nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? Excerpt from The Rock, 1930, T.S. Elliot [Image source: www.]
  • 60. 60© 2009 Stephen Few, Perceptual Edge O perpetual revolution of configured stars, O perpetual recurrence of determined seasons, O world of spring and autumn, birth and dying! The endless cycle of idea and action, Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of The Word. All our knowledge brings us nearer to our ignorance, All our ignorance brings us nearer to death, But nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? Excerpt from The Rock, 1930, T.S. Elliot [Image source: www.shepherdpics.com]
  • 61. 61© 2009 Stephen Few, Perceptual Edge O perpetual revolution of configured stars, O perpetual recurrence of determined seasons, O world of spring and autumn, birth and dying! The endless cycle of idea and action, Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of The Word. All our knowledge brings us nearer to our ignorance, All our ignorance brings us nearer to death, But nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? Excerpt from The Rock, 1930, T.S. Elliot [Image source: www.i163.photobucket.com]
  • 62. 62© 2009 Stephen Few, Perceptual Edge O perpetual revolution of configured stars, O perpetual recurrence of determined seasons, O world of spring and autumn, birth and dying! The endless cycle of idea and action, Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of The Word. All our knowledge brings us nearer to our ignorance, All our ignorance brings us nearer to death, But nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? Excerpt from The Rock, 1930, T.S. Elliot [Image source: www.jamin.org]