What Are The Most Common APA Style Mistakes Done By Students?

Following our tradition from 2010 and 2011, we present you an overview of the aspects of APA style that students find the most difficult. The data was collected from the manuscripts submitted to us in 2012. Just as in the previous two posts, we were more interested in the type of mistakes that students do, rather than their quantity. In this year’s analysis, more categories have been included compared with the previous two (27 in total), which allowed us to conduct a more detailed investigation on common APA style mistakes. This was done by identifying the mistake categories with the highest frequencies from the papers submitted to us. This post will guide you through the most common APA style mistakes and offer you advice on how to avoid them when writing your own paper. We will start off with the general formatting of the paper; then, we will move on to citing sources and formatting the reference list.

General Formatting

Running Head and Page Numbers

Surprisingly, 86.3% of all papers either did not have a running head or a running head that was formatted incorrectly. In addition to this, 75% of all students who submitted a paper to us either did not include page numbers or, those that did, did not format them correctly.

Advice: The running head is a shorter version of the title that appears in the header of all pages. Even before you start writing the paper, make sure that you include a running head and page numbers in the text file. Also, check the proper way to format them according to the 6th Publication Manual of the American Psychological Association (APA, 2009). Pay attention to the alignment, size, font and character length of the running head. Also, make sure that the page numbers appear in the upper right corner of the page.


In 2012, 72.7% of the authors who submitted a paper to us didn’t format the “Abstract” heading correctly or didn’t have an abstract in the first place.

Advice: The abstract is an essential part of your paper, so you should always make sure that you have one! Also, make sure that the abstract appears on a separate page and that its heading is formatted correctly. One common mistake that a lot of students do is formatting the heading in bold and/or italics. Quite on the contrary, this heading should be centered and formatted as the rest of the text. You can find more information about the abstract by checking our post on how to write a good abstract.


In addition to problems with the abstract, 61.3% of the students who submitted to us did not include keywords in their paper. Keywords are very important, because they are used by indexing services and search engines to deliver the content that the user is searching for.

Advice: Keywords should be situated below the abstract and be formatted according to the recommendation in the 6th Publication manual (APA, 2009).


Most of the students who submitted their manuscripts to JEPS were confused with the format of their headings. In fact, 86.3% of all papers had headings that were either of incorrect level or otherwise had problems with their format.

Advice: The headings are always one of the difficult parts when it comes to formatting your paper in APA style. The first thing you should do is to check the 5-level heading structure that can be found in the 6th Publication Manual (APA, 2009). Headings in research articles are easier to format because they follow a similar structure. However, literature review articles can be a bit more challenging. Any headings that appear at the same level should be equally important in the point you are trying to make. Headings that are level 2, 3 and so on usually elaborate on the section that they appear in. You can find additional information in our Bulletin post on how to format headings in APA style.

In-text Citations

Eighty-four percent of all papers submitted to us in 2012 had problems with in-text citations. Mistakes in this category include: incorrect use of ‘et al.’, spelling inconsistencies, incorrect use of commas and ampersands, as well as wrong order of multiple citations in a single parenthesis.

Advice: Citing sources accurately is an essential part in writing your paper. Make sure that you know the rules for citing works written by different number of authors. Additionally, check whether the names and the year of publication of your citations have been consistent throughout the text. If you find the authors’ names difficult to spell, use Copy and Paste to avoid mistakes. Be careful not to omit the comma and ampersand when citing a work written by three or more authors. Finally, do not forget that you need to order alphabetically all multiple citations that appear in a single parenthesis.

Other Less Common Mistakes

Figure 1 shows APA style mistakes that were encountered less frequently in the papers submitted to us, but that nonetheless constituted a significant part of all mistakes across the 27 categories.

 Figure 1. Other less common APA style categories that students found difficult in 2012.

Advice: You should leave out all personal information in the text and then delete the file’s meta-data in order to ensure that the blind-review procedure is followed. To delete the file’s metadata, simply go to the “Properties” menu in Word and delete the information in the “Author” field. The same thing can be done by right-clicking on the text file in Windows Explorer and choosing “Properties”.

JEPS requires that all manuscripts submitted to us have the correct margin format specified in our guidelines (2.54 cm for right and left margins, 3.0 cm for up and down margins). It’s good to start with these small details before the actual writing of the paper, since you can very easily forget about them later on.

Quotations can also cause some difficulties to students. One mistake that a lot of authors commit is that they forget to provide page numbers for direct quotations. It’s good to avoid this type of mistake because it can be time-consuming to go back and search for the page that the quotation was taken from, especially if you have quoted a lot of materials. Also, do not forget that there are different rules for quoting text that is longer than 40 words (see APA, 2009).

Reference List

Layout Formatting

Seventy-seven percent of all authors who submitted to us in 2012 did not format the “References” heading correctly or did not include one in the first place. This result is very similar to the one concerning the “Abstract” heading because those two types of headings are formatted in the same way.

Advice: Before even writing your references, always make sure that you have a “References” heading. It should be centered and formatted just like the rest of the text.


The data analysis shows that 90.9% of all authors made three or more mistakes when formatting their references. While this number is very impressive, it includes a number of APA style mistakes such as: incorrect use of commas, full stops, ampersands, italics, or overall incorrect formatting of the different types of references.

Advice:  The easiest way to avoid mistakes in the reference list is to use referencing software- there are some freeware programs that will do a very good job. They will save you a lot of frustration and also make it easier for you to organize your references. You can check our post that introduces a similar program. If you still want to format the reference list on your own, make sure that you know how to format the different types of references (e.g. books, journal articles, dissertations). Most of the other rules, such as the use of punctuation marks and formatting the title, follow the same logic and are relatively easy to learn. Here are a few very common mistakes in this category:

  • One thing that a lot of students do is that they capitalize all major words in the title of the reference. You should remember that only the first word should be capitalized. If the title contains a colon or dash, the word immediately after it should also be capitalized.
  • Be careful not to omit the ampersand when writing the reference for a work written by 2 or more authors.
  • Make sure that you use intervals correctly- especially when writing the authors’ initials.

Further reading on the JEPS Bulletin: APA style: How to format the references list?

Digital Object Identifier (DOI)

Of all the papers that we received in 2012, 88.6% had one or more omitted DOIs. Providing DOIs for journal articles may seem like a trivial thing to do and that’s probably one of the reasons why a lot of students failed to do so.

Advice: Journal articles that are published online usually provide a DOI on the first page. Also, most journal publishers provide this kind of information on their website. A lot of articles that have been published in the last 10 to 15 years normally have DOIs, but it’s best if you check whether each article you are referencing has one. You can learn more about DOIs here.

In addition, there are some other less common APA style mistakes in referencing sources, as presented in Figure 2.

 Figure 2. Other common APA style mistakes in the reference list.

Referring to mistakes made by students in the section of the references is the failure to list all cited sources in the reference list. This mistake can easily go unnoticed when you cite sources, but leave writing the references for later. The easiest way to avoid this mistake is to provide a reference for the cited source right away. Also, you can use the search engine in Word to see if all cited sources appear in the reference list (and vice versa). This strategy is also very effective for finding spelling inconsistencies between in-text citations and the reference list, a mistake that some 45% of the authors did.

While the correct formatting of your references is important, you should also pay attention to the general layout formatting of the reference list. For example, it should begin on a new page and the references should be formatted with hanging indentation (see APA, 2009).

Additionally, make sure that the references are ordered correctly. They should be ordered 1) alphabetically and 2) according to the number of authors and year of publication (if applicable).


With so many rules to remember, formatting your paper in APA style can be tricky. However, with a little patience and experience you will quickly grasp the basic rules. If you ever need help with an APA style question, you can always ask it in the APA style Q&A section of our website.


I would like to thank the JEPS team members, and especially Ezra Bottequin, who helped me collect the data for this post.


American Psychological Association. (2009). Publication manual of the American Psychological Association (6th ed.). Washington DC: Author.


Photo credit: morgueFile.com


Martin Vasilev

Martin Vasilev

Martin Vasilev is a final year undergraduate student of Psychology at the University of Sofia, Bulgaria, and the author of some of the most popular posts on JEPS Bulletin (see for example, his post on the most common mistakes in APA style was the most read in the JEPS Bulletin in 2013 and his post on writing literature reviews, which was reprinted in the MBA Edge, a magazine for prospective postgraduate students in Malaysia)

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