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Chapter 2: Displaying and describing categorical data - Coggle Diagram
Chapter 2: Displaying and describing categorical data
We want to see patterns, relationships, trends and exceptions
Three rules of data Analysis:
Make a picture because it is the best way to TELL other about data
Make a picture to SHOW the important features and patterns
Make a Picture to help you THINK about patterns and relationships
Area Principle:
The area occupied by a part of the graph should correspond to the magnitude of the value it represents
Frequency Tables
Frequency tables: record the total counts and the category name
categories label the rows
show count
Relative Frequency tables
Proportion: divide counts by total number cases
multiply by 100 to show them as percentages
describe distribution
Charts
Categorical Data condition: the data are counts or percentages of individuals in categories
Pie charts
show the whole group of cases as a circle
slice circle in pieces whose sizes are proportional to the fraction of the whole in each category
Bar Charts
displays the distribution of a categorical variable, showing the counts for each category next to the other for easy comparison
Relative frequency bar charts --> replacing counts with percentages
Segmented Bar Charts
treats each bar as the whole and divides it proportionally into segments corresponding to the percentage in each group
Contingency Tables
show how the individuals are distributed along each variable, contingent on the value of the other variable
each cell gives count for combination of the values of the two variables
marginal distribution: the frequency distribution of one of the variables
when the distribution of one variable is the same for all categories of another, the variables are INDEPENDENT
Conditional distributions:
they show the distribution of one variable for just those cases that satisfy condition of another variable