12 | Helpful Tools to Improve the Flow of Logic in Scientific Papers and Proposals

Just as a surgeon would not begin a surgery without scalpels, scissors, forceps, and clamps, a scientist should not begin a writing project without knowing how to use a few linguistic tools to optimize the flow of logic. In papers and proposals with clear logic flow, the content can be understood easily and the reader can move effortlessly from sentence to sentence. Any text that causes the reader to pause to comprehend what is being communicated is problematic. Five techniques to optimize the flow of logic, when applied at either the macro level (to the whole paper) or micro level (to words within a sentence), are as follows.

1. Well-structured outlines. Construct an outline of the main topics that will be presented prior to engaging in the writing process—this is a surefire way to achieve a clear flow of logic. Outlines help authors maintain focus and avoid tangents, thereby supporting clarity and conciseness. Hence, invest the time upfront to develop a well-structured outline (or at least a list of bullet points containing the key messages).
2. Strong topic sentences. Begin paragraphs with a topic sentence that provides a unifying theme for the sentences that follow. A good topic sentence will improve coherency within the text and serve as a guide for your audience, which consists of busy scientists who often skim through documents. The text below in bold illustrates how the addition of a topic sentence can improve the flow (data are from the National Center for Health Statistics^[1]):
   • Without a topic sentence: Heart disease caused 702,880 deaths in the United States in 2022. Cancer caused 608,371 deaths in the United States in 2022. Accidents caused 227,039 deaths in the United States in 2022.
   • With a topic sentence: The leading causes of death in the United States in 2022 were heart disease, cancer, and accidents. Heart disease caused 702,880 deaths, cancer caused 608,371 deaths, and accidents caused 227,039 deaths.
3. Parallel constructions. Use the same grammatical structure in headers, specific aims statements, paragraphs, sentences, tables, and figures because parallelism is critical to achieving a clear flow of logic. These phrasings have a parallel structure: identify, determine, assess; these phrasings do not: identify, determination, assessing. Similarly, if the topic sentence states that you collected data during week 1, week 4, and week 12, discuss the data in that order to maintain a parallel structure. Parallel constructions facilitate understanding in a profound way. This will be one of the sharpest tools in your toolbox.
4. Transitional expressions. Let the reader know what to expect with transitional expressions. Common ones used in scientific papers include however, additionally, furthermore, importantly, subsequently, consequently, therefore, hence, thus, and finally. More examples can be found in the logical relationship–transitional expression table created by the Writing Center at University of North Carolina at Chapel Hill.^[2]
5. Upfront context statements. Move ending phrases that give temporal or spatial context to a sentence, such as “in earlier experiments” and “in several patients,” to the first part of a sentence. Readers will then immediately understand the context for the information that comes next.
6. Obvious subjects. Scrutinize the use of “it” and “this/these” for brevity. Often the use of such terms is entirely appropriate, but be sure that readers will not need to waste precious time figuring out the correct subject. This can occur if “it” or “this/these” could refer to more than one noun in the preceding text. Simply replacing the words “it” and “this/these” with more specific terminology in such situations can prevent any misunderstanding.