Introduction to Data Analytics

Introduction to Data Analytics

• 1. Slide52 Introduction to Data Analytics
• 2. Slide53 What makes a good chart?
• 3. Slide55 What makes a good chart?
• 4. Slide56 What makes a good chart?
• 5. Slide54 Some basic principles (adapted from Tufte 2009) Tufte’s fundamental principle: Above all else show the data
• 6. Slide57 Principle 1: The chart should tell a story
• 7. Slide58 Examples?
• 8. Slide59 Telling a Story
• 9. Slide60 Principle 2: The chart should have graphical integrity
• 10. Slide61 Examples of the “lie factor” Reprinted from Tufte (2009), p. 57 & p. 62
• 11. Slide62 A more recent, basic example The original graphic from Real Clear Politics, 2008. (Look at the y-axis) The adjusted graphic.
• 12. Slide63 Other tips to avoid “lying”
• 13. Slide64 Principle 3: The chart should minimize graphical complexity Generally, the simpler the better…
• 14. Slide65 When a table is better than a chart •For a few data points, a table can do just as well…
• 15. Slide66 The Ultimate Table: The Box Score Large amount of information in a very small space So why does this work? Depends on the reader’s knowledge of the data
• 16. Slide67 The Business Box Score? •Applying the same concept to our salesforce example. •How does this help? How could it hurt?
• 17. Slide69 Data Ink Tufte’s principle: Erase ink whenever possible
• 18. Slide70 Being conscious of data ink Lower data-ink ratio (worse) Higher data-ink ratio (better)
• 19. Slide71 What makes a good chart? Sometimes it’s really a matter of preference. These both minimize data ink. Why isn’t a table better here?
• 20. Slide74 3-D Charts Evaluate this from a data-ink perspective. How does it affect the clarity of the chart?
• 21. Slide72 Chartjunk: Data Ink “gone wild”
• 22. Slide73 Example: Moiré effects (Tufte2009)
• 23. Slide75 Example: The Grid Why are these examples of chartjunk? What could you do to remedy it?
• 24. Slide76 Data Ink Working Against Us Evaluate this chart in terms of Data Ink. Are there better visualizations?
• 25. Slide77 Data Ink Working For Us Evaluate this chart in terms of Data Ink. Imagine this as a bar chart. As a table!!
• 26. Slide78 Stacked Bar Charts are Often Trouble •Original chart from the BBC website •Why is this so difficult to read? •What would be a better way to visualize it?