- Pie Charts – severe perceptual problems, hard to interpret – try not to use them!
- marginal distribution – in a contingency table, the distribution of either variable alone.
or bottom row) of the table.
Chapter 4 displaying and describing categorical data. Display data help see what you are not likely to see in table help plan approach to analysis shows important features, patterns and relationships reveals extraordinary (or possible wrong) data. Best way to report data to others. Frequency tables shows number of cases (ex. website visits) for each category and records totals and category names (ex. provinces) Describe the distribution of a categorical variable name possible categories and tell how frequently each occurs. Relative frequency table displays percentages, rather than the counts, of each of the value in each category. The area principle the area occupied by a part of the graph should correspond to the magnitude of the value it represents. Bar charts displays the distribution of a categorical variable, showing the counts for each category next to each other for easy comparison. More accurate visual impression of the distribution common base, freestanding, spaces in-between.