How data is displayed
Displaying Sets Of Data
Categorical subdivisions are compared against a reference. A bar chart can show comparison of the actual versus the reference amount.
Comparison between observations represented by two variables (X,Y) to determine if they tend to move in the same or opposite directions. For example, plotting someone’s weight (X) and their height (Y). A scatter plot is typically used for this message.
A single variable is captured over a period of time, such as the inflation rate over a 10-year period. A line chart may be used to demonstrate the trend.
Categorical subdivisions are measured as percentage. A pie chart or bar chart can show the comparison of ratios, such as the market share represented by competitors in a market.
Categorical subdivisions are listed in ascending or descending order, such as school class sizes (the measure) by year group (the category, with each year groupo a categorical subdivision) in a school year. A bar chart may be used to show the comparison across the year group.
Shows the number of observations of a particular variable for given interval, such as the number of years in which the stock market return is between intervals such as 0-10%, 11-20%, etc. A histogram, a type of bar chart, may be used for this analysis. A boxplot helps visualize key statistics about the distribution, such as median, quartiles, outliers, etc.
Comparison of a variable across a map or layout, such population by country or the number of persons on the various floors of a building. A cartogram is a typical graphic used.
Comparing categorical subdivisions in no particular order, such as the sales volume by product code. A bar chart may be used for this comparison.
Analysts reviewing a set of data may consider whether some or all of the messages and graphic types above are applicable to their task and audience. The process of trial and error to identify meaningful relationships and messages in the data is part of data mining.
