Microsoft Office Tutorials and References

In Depth Information

Save this ﬁle as: BEE12

Print out both the data table and the ANOVA summary table so that all of this

information ﬁts onto one page. (Hint: Set the Page Layout/Fit to Scale to 85 %

size).

As a check on your analysis, you should have the following in these cells:

A20: Anova: Single Factor

D25: 14.66

B26: 12

D32: 1.67

E31: 8.19

G31: 3.32

Now, let’s discuss how you should interpret this table:

8.2 How to Interpret the ANOVA Table Correctly

Objective: To interpret the ANOVA table correctly

ANOVA allows you to test for the differences between means when you have

three or more groups of data. This ANOVA test is called the F-test statistic, and is

typically identiﬁed with the letter: F.

The formula for the F-test is this:

F
¼
Mean Square between groups

ð

MS
b

Þ
divided by Mean Square within

groups MS
w

ð

Þ

F
¼
MS
b
=
MS
w

ð
8
:
1
Þ

The derivation and explanation of this formula is beyond the scope of this Excel

Guide. In this Excel Guide, we are attempting to teach you how to use Excel, and

we are not attempting to teach you the statistical theory that is behind the ANOVA

formulas. For a detailed explanation of ANOVA, see Gould and Gould (
2002
) and

Weiers (
2011
).

Note that cell D31 contains MS
b
= 13.66, while cell D32 contains MS
w
= 1.67.

When you divide these two ﬁgures using their cell references in Excel, you get

the answer for the F-test of 8.19 which is in cell E31. (Remember, Excel is more

accurate than your calculator!) Let’s discuss now the meaning of the ﬁgure:

F = 8.19.

In order to determine whether this ﬁgure for F of 8.19 indicates a signiﬁcant

difference between the means of the three groups, the ﬁrst step is to write the null

hypothesis and the research hypothesis for the three subspecies of honey bees.

Search JabSto ::

Custom Search