In an increasingly data-driven world, it is more important than ever for students as well as professionals to better understand basic statistical concepts. 100 Questions (and Answers) About Statistics addresses the essential questions that students ask about statistics in a concise and accessible way. It is perfect for instructors, students, and practitioners as a supplement to more comprehensive materials, or as a desk reference with quick answers to the most frequently asked questions.

How Can I Use a Matrix to Display Several Correlation Coefficients?

How Can I Use a Matrix to Display Several Correlation Coefficients?

A single correlation coefficient is always expressed as one value—a numerical index of the strength of the relationship between two, and only two, variables.

If more than two variables are being correlated with one another, then a correlation matrix can help consolidate the information about the data and make the various relationships much easier to understand.

For example, here are some data, and the data table is followed by a matrix that reflects the various correlations that might be computed. Remember that simple Pearson product-moment correlations always reflect the correlation between just two variables.

Here are the data, with each variable named and the possible range in parentheses.

Year in School (1–4)

GPA (0.0–4.0)

Study Hours (0–40)

Boredom Scale (1–100)

1

3.3

23

16

2

3.2

24

26

2

2.8

12

28

3

3.0

12

11

1

1.8

18

57

2

1.8

7

69

3

2.8

22

58

4

2.3

25

44

3

4.0

30

4

4

2.7

9

29