Histograms and Charts FSE 200

Why Illustrate Data? When describing a set of scores, you will want to use two things… –One score for describing the group of data Measure of Central Tendency –Measure of how diverse or different the scores are from one another Measure of Variability –However, a visual representation of these measures is much more effective when examining distributions

Minimize the “junk” Plan before you start creating Say what you mean…mean what you say Label everything Communicate one idea Keep things balanced Maintain the scale in the graph Remember…simple is best Limit the number of words The chart should convey what you want to say Ten Ways to a Great Figure

Parts of a Chart

Frequency Distributions Method of tallying and representing the number of times a certain score occurs –Group scores into interval classes/ranges Creating class intervals –Range of 2, 5, 10, or 20 data points –10-20 data points cover entire range of data –List class interval with a multiple of the interval –Largest interval goes at the top

Histograms Class intervals along the x axis

Histograms A hand drawn histogram

Histograms Tallying scores

Excel’s Histogram Tool Histogram data

Excel’s Histogram Tool Creating bins

Excel’s Histogram Tool The data analysis dialog box

Completed Histogram The completed histogram dialog box

Completed Histogram The finished ToolPak histogram

Frequency Polygon “a continuous line that represents the frequencies of scores within a class interval”

Frequency Polygon A hand drawn frequency polygon

Fat and Skinny of Frequency Distributions Distributions can be different in four ways… –Average value –Variability –Skewness –Kurtosis

Average Value How distributions can differ in their average score

Variability How distributions can differ in variability

Skewness Positive and negative skewness Degree of skewness in different distributions

Kurtosis Degrees of kurtosis in different distributions

Excellent Charts Column chart Creating a simple column chart

How to Create Charts in Excel The All Chart Types dialog box

How to Create Charts in Excel Click Chart Type Click Finish A simple column chart

Other Cool Charts A line chart showing trend over time

Other Cool Charts A pie chart of voters by party

Acknowledgement The majority of the content of these slides were from the Sage Instructor Resources Website