ABBREVIATIONS &
STATISTICS
APA 6th Edition
Trae Stewart, Ph.D., Associate Professor & EDCL Program Coordinator
Zane Wubbena, M.A., Ph.D. Student – School Improvement
(Updated July 2014)
Overview
 APA 6th Edition
 Abbreviations
– General Use
– Latin Abbreviations
– Examples
 Statistics & Variables
–
–
–
–
Singular vs. Plural
Written vs. Abbreviated
When to Use Italics
Examples
 Helpful Resources
Abbreviations
(General Use)
 Use an abbreviation only after introducing the term and
abbreviation.
Example: According to the American Psychological Association (APA),
abbreviations are best used only when they allow for clear communication.
See below for exceptions to this APA format guideline.
 Exceptions
– Write out unless used at least 4 times
– Common abbreviations do not need to be written (e.g., IQ, HIV)
– Do not use abbreviations in reference list
Example: The Centers for Disease Control and Prevention
would not be abbreviated as CDC in references
– When using units of measure with a numerical value, do not
write out the measure. If no number, then write out the unit.
Example: 12 g vs. “several grams”
Abbreviations
(Latin Abbreviations)
 Purpose: to replace
common argumentative
phrases without taking
up much space or
distracting readers
 Ensure that the
abbreviation is within
parentheses
– (e.g.)
 If not in parentheses,
then write out the
English translation
– for example
Abbreviation
English
i.e.
that is
e.g.
for example
etc.
and so forth
vs.
versus
cf.
compare
ed.
edition
n.d.
no date
viz.
namely
et al.
and others
Abbreviations
(Examples: Latin Abbreviations)
Example 1
In text, no abbreviations:
The subjects were asked to describe their feelings—that is, their
moods, perceptions, and emotions—in the box provided on the
survey form.
In parenthetical form, with abbreviations:
The subjects were asked to describe their feelings (i.e., their moods,
perceptions, and emotions) in the box provided on the survey form.
Example 2
In text, no abbreviations:
Survey respondents ranked their choices in order of preference,
first, second, third, and so forth.
In parenthetical form, with abbreviations:
Survey respondents ranked their choices in order of preference
(first, second, third, etc.).
Statistics & Variables
(Singular vs. Plural)
 Sentence syntax determines singular or plural
variable use
 All plural abbreviated forms are made by
adding a non-italic lowercase “s”
 Do not use an apostrophe plus an “s,” an italic
“s,” or a capital “S.”
 Incorrect: ps < .05, p’s < .05; Ms = 3.70 and 4.22; Means
= 3.70 and 4.22; degree’s of freedom.
 Correct: ps < .05; Ms = 3.70 and 4.22; degrees of
freedom.
Statistics & Variables
(Written vs. Abbreviated)
 Use the written-out form of the variable in
prose; use the symbol in conjunction with all
mathematical operators (such as the equals
sign or the greater than/less than signs).
 As usual, use singular or plural as needed by
the context.
Statistics & Variables
(Italics)
 Variables are italicized.
 Superscript numbers are not italicized
-
R2
 Identifiers (which can be superscript or
subscript words, letters, or numbers) are not
italicized.
-
If Mgirls = 4.22 and Mboys = 3.78, the symbol for mean
is italicized, but the nonvariable identifiers (here
identifying the two groups, “girls” and “boys”) are not
italicized.
Statistics & Variables
(Abbreviation Chart)
Written-out form
Abbreviation/symbol
Singular
Plural
Singular
Plural
Cohen’s d
Cohen’s ds
d
ds
degree of freedom
degrees of freedom
df
dfs
F statistic or F value
F statistics or F values
F
Fs
mean
means
M
Ms
sample size (subsample)
sample sizes (subsample)
n
ns
sample size (full sample)
sample sizes (full sample)
N
Ns
p value
p values
p
ps
r value
r values
r
rs
R2
R2s
R2
value
R2
values
standard deviation
standard deviations
SD
SDs
standard error
standard errors
SE
SEs
t value
t values
t
ts
z score
z scores
z
zs
Cronbach’s alpha
Cronbach’s alphas
Cronbach’s α
Cronbach’s αs
beta
betas
β
βs
chi-square
chi-squares
χ2
χ2s
delta
deltas
Δ
Δs
Statistics & Variables
(Example: Results)
Helpful Resources
Purdue OWL
APA 6th edition Manual
Visit Other
APA Style (6th ed.) Modules
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