1. APA Style
Italics
Brackets
Parenthesis

2. Use of Italics
• Titles of books, periodicals, films, videos, TV
shows, and microfilm publications
American Psychologist
• Genera, species, and varieties
Macaca mulatta
• Introduction of a new, technical, or key term or label
(after a term has been used once, do not italicize it)
The term backward masking
box labeled empty
• A letter, word, or phrase cited as a linguistic example
words such as big and small

3. Use of Italics (continued)
• Words that could be misread
the small group
[meaning a designation, not group size]
• Letters used as statistical symbols or algebraic variables
a/b = c/d
• Some test scores and scales
MMPI scales: Hs, Pd
• Periodical volume numbers in reference lists
American Psychologist, 26, 46 – 67
• Anchors of a scale
health ratings ranged from 1 (poor) to 5 (excellent)

4. Do Not Use Italics
• Foreign phrases and abbreviations common in
English
a priori per se
• Chemical terms
NaCl
• Trigonometric terms
sin, tan, log
• Nonstatistical subscripts to statistical symbols or
mathematical expressions
Fmax S +S
A B

5. Do Not Use Italics (continued)
• Greek letters
β
• Mere emphasis (Italics are acceptable if emphasis
might otherwise be lost; in general, however, use
syntax to provide emphasis)
Incorrect:
it is important to bear in mind…
• Letters used as abbreviations
intertrial interval (ITI)

6. Use Brackets
• To enclose the values that are limits of a
confidence interval
95% Cls [-7.2, 4.3], [9.2, 12.4],
and [-1.2, -0.5]
• To enclose material inserted in a quotation by
some person other than the original writer
“when *his own and others’+ behaviors
were studied”

7. Use Brackets (continued)
• To enclose parenthetical material that is already
within parentheses
(The results for the control group [n = 8] are
also presented in Figure 2.)
Exception 1: Do not use brackets if the material can be
set of easily with commas.
(as lmai, 1990, later concluded)
Exception 2: In mathematical material, the placement
of brackets and parentheses is reversed; that
is, patentheses appear within brackets.

8. Do Not User Brackets
• To set off statistics that already include
parentheses
Correct:
was statistically significant, F(I, 32) = 4.37, p = 0.45
Incorrect:
was statistically significant (F[I, 32] = 4.37, p = 0.45)

9. Use Parentheses
• To set off structurally independent elements
The patterns were statistically significant
(see Figure 5).
• To set of reference citations in text
Dumas and Dore (1991) reported
• To introduce an abbreviation
effect on the galvanic skin response (GSR)
• To set off letters that identify items in a series within a
sentence of paragraph
The subject areas included (a) synonyms associated
with cultural interactions, (b) descriptors for ethnic
group membership, and © psychological symptoms.

10. Use Parentheses (continued)
• To group mathematical expressions
(k – 1)/(g – 2)
• To enclose the citation or page number of a direct
quotation
The author stated, “The effect disappeared
within minutes” (Lopez, 1993, p.311)
• To enclose numbers that identify displayed
formulas and equations
a = b + c (1)

11. Use Parentheses (continued)
• To enclose statistical values
was statistically significant (p = .031)
• To enclose degrees of freedom
F(2, 116) = 3.71

12. Do Not User Parentheses
• To enclose material within other parentheses
(the Beck Depression Inventory [BDI])
[Use brackets to avoid nested parentheses.]
• Back to back
Correct:
(e.g. defensive pessimism; Norem &
Cantor, 1986)
Incorrect:
(e.g. defensive pessimism) (Norem &
Cantor, 1986)