1. Incorrect title case. Titles of articles, books, and reports should be written in title case, meaning that only the first word and any proper nouns should be capitalized. For example, "The Influence of Social Media on Adolescent Development" instead of "THE INFLUENCE OF SOCIAL MEDIA ON ADOLESCENT DEVELOPMENT."
2. Missing or incorrect date. The publication date should be included in the reference list entry for all sources. For articles, this is the year of publication. For books, it is the year of the most recent edition.
3. Incorrect journal name abbreviation. Journal names should be abbreviated according to the style specified in the APA Publication Manual. For example, "Journal of Experimental Psychology: General" should be abbreviated as "J. Exp. Psychol. Gen."
4. Incorrect page number format. Page numbers should be written in Arabic numerals, not Roman numerals. For example, "p. 123" instead of "p. CXXIII."
5. Missing or incorrect DOI. The Digital Object Identifier (DOI) should be included in the reference list entry for all articles and books that have one.
6. Inconsistent formatting. The same formatting style should be used throughout the reference list. For example, all journal names should be either italicized or not italicized, and all page numbers should be written in the same format.
7. Plagiarism. It is important to give proper credit to the original authors of any ideas or information that you use in your writing. This can be done by citing the source in the text of your paper and including a full reference list entry for the source in the reference list.
8. Use of et al. incorrectly. The term "et al." should only be used when there are more than two authors of a work. For example, "Smith et al. (2020)" instead of "Smith, Jones, and Williams (2020)."
9. Incorrect hanging indent. The second and subsequent lines of each reference list entry should be indented 0.5 inches from the left margin.
10. Not double-spacing the reference list. The entire reference list should be double-spaced, including the space between reference list entries.