Parallel Headings in Research Papers

The MLA Handbook offers guidance about styling headings and subheadings in research papers in section 1.5 (4–5). Formatting headings is one thing, but what about writing them? This post offers advice about one aspect of writing headings: parallel structure. Parallel structure means that corresponding components match one another grammatically and share other basic similarities. When headings are parallel, readers can more easily grasp the structure and content of a research project as a whole. This post discusses several ways to achieve parallelism in headings.

First, a quick review of levels of headings. A research project might have no headings other than its title, or it might have one or multiple levels of headings. Because headings help organize and structure a project, longer and more complex projects, such as a thesis, a dissertation, or a book, may benefit from more levels of headings than shorter projects do. In a dissertation, for example, the first level of headings might be the chapter titles. If a chapter has subheadings, they are subordinate to the chapter title, and each subsequent level of headings is subordinate to the level above it. Parallelism in headings can apply across all headings, within a given level of headings, or both.  

Grammatical Parallelism

Text has parallel structure when its corresponding elements are of the same grammatical category. In the following, all headings except the last one consist of noun phrases. Consider revising the heading “Who Wants Dessert?” so that it is parallel with the others.

Agreement in Number

If headings use a mix of singular and plural nouns, see if you can adjust them so that they are all singular or all plural. In the headings below, “Dessert” could become “Desserts.”

Subtitles

If you have a mix of headings with and without subtitles, consider editing them so that all headings at the same level either contain a subtitle or do not. In the following, give “Main Dishes” a subtitle if you decide to retain subtitles in the other headings.

Length

The MLA Handbook advises keeping headings short (4). If you can, make all headings of the same level roughly the same length. That doesn’t mean that all headings have to contain exactly five words. But a review of your headings for length may quickly identify any outliers. If a heading contains things like titles of works or quotations, consider removing them from the heading and mentioning them only in the body text. Because the first heading below is much longer than the others, consider replacing the quotation with a shorter main title or shortening the subtitle.

Work Cited

MLA Handbook. 9th ed., Modern Language Association of America, 2021.