How to display data badlyUsing Microsoft Excel to obscure your data and annoy your readersInspirationGeneral principlesExample 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 2Example 2Example 2Example 2Example 2Example 2Example 3Example 3Example 3Example 3Example 4Example 4Example 4Example 5Example 5Example 5Example 5Example 5Example 5Example 6Example 6Example 6Example 6Example 7Example 7Example 8Example 8Displaying data wellFurther readingThis work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike License. Your use of this material constitutes acceptance of that license and the conditions of use of materials on this site.Copyright 2006, The Johns Hopkins University and Karl W. Broman. All rights reserved. Use of these materials permitted only in accordance with license rights granted. Materials provided “AS IS”; no representations or warranties provided. User assumes all responsibility for use, and all liability related thereto, and must independently review all materials for accuracy and efficacy. May contain materials owned by others. User is responsible for obtaining permissions for use from third parties as needed.How to display data badlyKarl W. BromanDepartment of Biostatisticshttp://www.biostat.jhsph.edu/~kbromanUsing Microsoft Excel to obscure your data and annoy your readersKarl W BromanDepartment of Biostatisticshttp://www.biostat.jhsph.edu/~kbroman4InspirationThis lecture was inspired byH Wainer (1984) How to display data badly. American Statistician 38(2):137-147Dr. Wainer was the first to elucidate the principles of the bad display of data.The now widespread use of Microsoft Excel has resulted in remarkable advances in the field.5General principlesThe aim of good data graphics:Display data accurately and clearly.Some rules for displaying data badly:– Display as little information as possible.– Obscure what you do show (with chart junk).– Use pseudo-3d and color gratuitously.– Make a pie chart (preferably in color and 3d).– Use a poorly chosen scale.– Ignore sig figs.6Example 17Example 18Example 19Example 110Example 111Example 112Example 113Example 114Example 2Distribution of genotypesAA 21%AB 48%BB 22%missing 9%15Example 216Example 217Example 218Example 219Example 220Example 321Example 322Example 323Example 324Example 425Example 426Example 427Example 528Example 529Example 530Example 531Example 532Example 533Example 634Example 635Example 636Example 637Example 738Example 739Example 840Example 841Displaying data well• Be accurate and clear.• Let the data speak.– Show as much information as possible, taking care not to obscure the message.• Science not sales.– Avoid unnecessary frills — esp. gratuitous 3d.• In tables, every digit should be meaningful. Don’t drop ending 0’s.42Further reading• ER Tufte (1983) The visual display of quantitative information. Graphics Press.• ER Tufte (1990) Envisioning information. Graphics Press.• ER Tufte (1997) Visual explanations. Graphics Press.• WS Cleveland (1993) Visualizing data. Hobart Press.• WS Cleveland (1994) The elements of graphing data. CRC