2022 Introduction to Statistics in Research Mitchell 2nd ed

I N T R O T O R E S E A R C H : D A T A V I S U A L I Z A T I O N & C O M M O N S T A T T E S T S

Comparative histogram: display two separate histograms with the same horizontal axis and relative frequency on the vertical axis. (Remember relative frequency requires you find the percentage for each count based on total). One thing to remember when working with data and this is best understood if an example is shown.

2009 Division 1 Basketball Playoff Dataset

NCAA has a tremendous amount of data on graduation rates for overall athletics as well as specific graduation rates by a type of sport. The file I downloaded from the NCAA website had over 6,000 rows of data ! Well, that’s just too much. Instead let’s look at this dataset from the 2009 Division I basketball playoffs.

The data is for 63 schools, but I’m only showing you a portion of the data, because I want you to understand how it must be set up in statistical software. The “All - BB” is the difference between all athletes percentage minus the basketball percentage.

Graduation Rates (%) School Basketball Athletes All - BB 1 63 75 12 2 56 57 1 3 31 86 55 Continues to 63 Table 99: 2009 Division 1 basketball playoffs and graduation rates

Table 98: Example of how to set up the data (this is in JMP)

Notice that the basketball and athletes percentages were both placed in the column under type in the statistical software. They both need to be in this column to create a comparative histogram.

In JMP statistical software, under Analyze and Distribution, set up the Y Columns as “Rates” and the by as “Type”

Let’s look at the output and analyze the comparison.

103