Slide 1Slide 2Types of Univariate Categorical DisplaysFrequency TablesRelative Frequency TablesRelative Frequency vs. PercentageFrequency Bar ChartRelative Frequency Bar Chart“Column Charts” from ExcelPareto ChartExample Pareto ChartPie ChartsPie Charts from ExcelWhat’s Wrong Here?Slide 15Types of Bivariate Categorical Data DisplaysContingency TablesContingency Tables (cont.)Contingency Tables (cont.)Contingency Tables (cont.)Conditional DistributionsConditional Distributions (cont.)Conditional Distributions (cont.)Conditional Distributions (cont.)Conditional Distributions (cont.)Segmented Bar ChartsClass Activity – Groups of 2 (or 3)Class ActivityClass ActivityMosaic PlotMosaic Plot (Cont.)Segmented Bar Chart vs. JMP’s Mosaic PlotAnother Example: 100 Randomly Selected UT Students100 Randomly Selected UT Students (Cont.)100 Randomly Selected UT Students (Cont.)100 Randomly Selected UT Students (Cont.)1Chapter02 Presentation 0115Copyright © 2014, 2012, 2009 Pearson Education, Inc.Chapter 2Displaying and DescribingCategorical Data2Chapter02 Presentation 0115Copyright © 2014, 2012, 2009 Pearson Education, Inc.2.1Summarizing and Displaying a Single Categorical VariableChapter02 Presentation 01153Copyright © 2014, 2012, 2009 Pearson Education, Inc.Types of Univariate Categorical DisplaysFrequency and Relative Frequency TableBar ChartPareto ChartPie ChartChapter02 Presentation 01154Copyright © 2014, 2012, 2009 Pearson Education, Inc.Frequency TablesThe name of each category, andthe number of observations in each category.Chapter02 Presentation 01155Copyright © 2014, 2012, 2009 Pearson Education, Inc.Relative Frequency TablesSimilar, but gives the percentages (instead of counts) for each category.Chapter02 Presentation 01156Copyright © 2014, 2012, 2009 Pearson Education, Inc.Relative Frequency vs. PercentageThe table on the previous page may be called a “relative frequency” table, but it is displaying percentages, not relative frequencies.Percentages will range from 0 to 100%Relative frequencies will range from 0 to 1.00ClassFrequencyRelative Frequency%First 325 0.1477 14.77Second 285 0.1295 12.95Third 706 0.3208 32.08Crew 885 0.4021 40.21Total 2201 1.000 100.0Chapter02 Presentation 01157Copyright © 2014, 2012, 2009 Pearson Education, Inc.Frequency Bar ChartA graphical display of the data in a frequency table.Chapter02 Presentation 01158Copyright © 2014, 2012, 2009 Pearson Education, Inc.Relative Frequency Bar ChartA graphical display of the data in a relative frequency table.Chapter02 Presentation 01159Copyright © 2014, 2012, 2009 Pearson Education, Inc.“Column Charts” from ExcelExcel can easily display both frequency and relative frequency bar charts. See the file Ch03_Titanic_Passengers.xlsxChapter02 Presentation 011510Copyright © 2014, 2012, 2009 Pearson Education, Inc.Pareto ChartA bar chart with the bars put in order from the most frequently occurring category on the left to least frequently occurring category on the right is called a Pareto Chart.Typically a Pareto Chart has a frequency scale on the left and a relative frequency scale on the right.Sometimes a Pareto Chart contains a line above the bars indicating cumulative frequency and cumulative relative frequency.Chapter02 Presentation 011511Copyright © 2014, 2012, 2009 Pearson Education, Inc.http://en.wikipedia.org/wiki/Pareto_chart 168 Late Arrivals to Work Example Pareto ChartChapter02 Presentation 011512Copyright © 2014, 2012, 2009 Pearson Education, Inc.Another common method of displaying categorical data:Pie ChartsChapter02 Presentation 011513Copyright © 2014, 2012, 2009 Pearson Education, Inc.Pie Charts from ExcelBoth frequency and relative frequency pie charts can be generated.If your audience is colorblind, these images will be difficult to make sense of.Chapter02 Presentation 011514Copyright © 2014, 2012, 2009 Pearson Education, Inc.What’s Wrong Here?This pie chart of the percentage of high-school students who engage in specified dangerous behaviors has a problem. Can you see it?15Chapter02 Presentation 0115Copyright © 2014, 2012, 2009 Pearson Education, Inc.2.2Exploring the Relationship Between Two Categorical VariablesChapter02 Presentation 011516Copyright © 2014, 2012, 2009 Pearson Education, Inc.Types of Bivariate Categorical Data DisplaysContingency TablesSide by Side Pie ChartsSegmented Bar ChartsMosaic PlotChapter02 Presentation 011517Copyright © 2014, 2012, 2009 Pearson Education, Inc.Contingency TablesA contingency table allows us to look at two categorical variables together. Example: we can examine the class of ticket and whether a person survived the Titanic:Chapter02 Presentation 011518Copyright © 2014, 2012, 2009 Pearson Education, Inc.Contingency Tables (cont.)Each cell of the table gives the count for a combination of values of the two variables.Chapter02 Presentation 011519Copyright © 2014, 2012, 2009 Pearson Education, Inc.Contingency Tables (cont.)The margins of the table, both on the right and on the bottom, give totals and the frequency distributions for each of the variables.Each frequency distribution is called a marginal distribution of its respective variable.The marginal distribution of Survival is:Chapter02 Presentation 011520Copyright © 2014, 2012, 2009 Pearson Education, Inc.Contingency Tables (cont.)The marginal distribution of Class is:Chapter02 Presentation 011521Copyright © 2014, 2012, 2009 Pearson Education, Inc.Conditional DistributionsA conditional distribution shows the distribution of one variable for just the individuals who satisfy some condition on another variable.The following is the conditional distribution of Survival, conditional on having been a crew member:24%76%100%Chapter02 Presentation 011522Copyright © 2014, 2012, 2009 Pearson Education, Inc.Conditional Distributions (cont.)The following is the conditional distribution of ticket Class, conditional on having survived:28.6%16.6%25.0%29.8%100%Chapter02 Presentation 011523Copyright © 2014, 2012, 2009 Pearson Education, Inc.Conditional Distributions (cont.)The following is the conditional distribution of ticket Class, conditional on having died:8.2%11.2%35.4%45.2%100%Chapter02 Presentation 011524Copyright © 2014, 2012, 2009 Pearson Education, Inc.Conditional Distributions (cont.)These last two conditional distributions tell us that there is a difference in class for
View Full Document
Unlocking...