Data Visualization Exam Questions with Verified Answers Latest Update 2024 (Graded A+)

Data Visualization Exam Questions with Verified Answers Latest Update 2024 (Graded A+) "The greatest value of a picture is when it forces us to notice what we never expected to see" - Answers John Tukey "Data viz is often the most effective way to describe, explore, and summarize a set of numbers by looking at a picture of those numbers... well-designed data graphics are usually the simplest and at the same time the most powerful" - Answers Edward Tufte (Visual display of quant info) Data visualization - Answers visual display of quantitative information through the use of -points -lines -coordinate systems -numbers -symbols -words -shading -color statistics - Answers graphical data analysis design - Answers communication and persception purposes of data visualizations - Answers explore: confirm and analyze explain: inform and persuade anscombe's quartet - Answers four datasets with the same properties (mean, sample variance, correlation) but very different graphs use tables when - Answers -the display will be used to look up individual values -precise values are required -the quantitative values include more than one measure -both detail and summary values are included -the display will be used to compare individual values use graphs when - Answers -the message is contained in the shape of the values -the display will be used to reveal relationships among whole sets of values representation summary - Answers -facilitate cognitive processing -some representations are innately better than others properties of representation - Answers -understanding without training -resistance to alternative conclusions -cross culture validity -immediacy (hard wired) perception in a nutshell - Answers specialized neurons extract features involuntarily -- rapid assembly of information into significance; object identification (and action) -- visual working memory (using three chunks) with active conscious attention gestalt principles of perception - Answers a psychological theory of perception that suggests the mind understands external stimuli as whole rather than the sum of their parts. the wholes are structured and organized using grouping laws principle of proximity - Answers we perceive objects close together as belonging to a group principle of similarity - Answers we tend to group objects together that are similar principle of enclosure - Answers we perceive objects as belonging together when they are enclosed in a way that appears to create a boundary around them principle of closure - Answers we perceive open, incomplete, and unusual forms as closed, whole, and regular principle of continuity - Answers we perceive objects that are connected as part of the same group visualization priniciples - Answers 1. adopt novel approaches to visualization only when anticipated benefits are greater than the cost of learning + cost of inconsistency 2. when two visualizations can support the same task, adopt the tool that is innately more effective 3. visualization tool development cost is less than benefits from visualization tool attention is drawn to - Answers contrasts, similarity the four key pre-attentive attributes - Answers form, color, position, motion pre-attentive processing - Answers occurs below the level of consciousness at an extremely high speed and is tuned to detect specific visual attributes form attributes - Answers -length -width -orientation -shape -size -enclosure -curvature -added marks color attributes - Answers -hue -intensity position attributes - Answers -2D position -motion nominal data - Answers multiple categorical states -urban/suburb/rural binary data - Answers two states -positive negative ordinal data - Answers categories with order -very happy to very sad -use a color scale interval data - Answers numbers with quantifiable differences -dates ratio - Answers meaningful zero where is the boundary - Answers -to show relationships consider consider linking graphical representations of data objects using lines or ribbons of colors -consider putting related information inside a closed contour -color or texture can be used to define regions that have more complex shapes motion attribute - Answers when animation is used in a visualization, aim for motion in the range of 0.5 to 4 degrees/second of a visual angle 5 things to know how people perceive charts - Answers 1. we don't go in order 2. we see first what stands out 3. we see only a few things at once 4. we seek meaning and make connections 5. we rely on conventions and metaphors common conventions - Answers -like colors mean like things -color saturation indicates higher and lower values -categories are arranged and plotted from one extreme to another common components of a chart/graph - Answers -title/subtitle -data region -data label -data encoding -annotation -legend -grind lines -note -x/y axis -tick mark scatterplot - Answers two continuous variables pie chart - Answers one continuous and one categorical variable line graph - Answers two continuous variables with one being time -doesn't need a zero bar chart - Answers one continuous and one categorical variable histogram - Answers one continuous variable glyphs - Answers symbols meant to represent a numerical attribute of an entity, representing through the use of our building blocks of form, color, position, and motion when developing glyphs - Answers use small, closed shapes to represent data entities, and use color, shape and size of those shapes to represent attributes of those entities when designing a set of glyphs to represent quantity - Answers mapping to any of the following glyph attributes will be effective: size (length/area), lightness, saturation, vertical position -never use volume of a 3D glyph to represent quantity to make symbols in a set maximally distinctive - Answers use redundant coding wherever possible, for example make symbols differ in both shape and color tufte's principles of graphical execellence - Answers 1. the well-designed presentation of interesting data- a matter of substance, statistics, and design 2. consists of complex ideas communicated with clarity, precision, and efficiency 3. that which gives to the viewer the greatest number of ideas in the shortest time with the least ink in the smallest space 4. nearly always multivariate 5. requires telling the truth about the data what should a good chart do? - Answers 1. show the data 2. induce the viewer to think about the substance rather than about methodology, graphic design, technology of graphic production 3. avoid distorting what the data has to say 4. present many numbers in a small space 5. make large data sets coherent 6. encourage the eye to compare different pieces of data 7. reveal the data at several levels of detail, from a broad overview to the fine structure 8. serve a reasonably clear purpose: description, exploration, tabulation, or decoration 9. be closely integrated with the statistical and verbal descriptions of a data set