The American Psychological Association style is widely used and accepted for academic writing in the sciences and social sciences. Clarifying connections among ideas is paramount in APA style, which sometimes requires numbering ideas in a list. Numbered lists fall under the “Headings and Seriation” APA guidelines according to the sixth edition of the "Publication Manual of the American Psychological Association."
Determine if your list is of a hierarchical or chronological nature. Lists that don’t have an order or rank of items should be presented in bulleted lists, not numbered ones, according to the APA.
Decide if you would prefer to present the materials in a list form or within the text of a paragraph. If you choose to present the material in the text of a paragraph, you may use letters instead of numbers for each section.
Follow one of the examples below when presenting your materials. If your information does not fit into either of these examples, consider using bullet points or writing the information in prose.
Example 1: Numbered list
After analyzing the results of the recent study, the American Dental Association recommended the following:
1. Brush your teeth at least twice a day. 2. Ensure that you are using proper technique and do not brush too vigorously. 3. Floss your teeth at least once a day.
Example 2: List within paragraph text
Following the ADA recommendations, the patients have (a) increased their brushing to twice per day, (b) reviewed and corrected their brushing technique, (c) have begun to integrate flossing into their daily routine.