Backtracking and continuity between sentences

Backtracking occurs when a reader must return to earlier text to identify a reference or reconstruct a relationship. Explicit references, repeated key terms and appropriate continuity markers help readers follow an argument from one sentence to the next.

Explicit references

Pronouns avoid repeating nouns, but an unclear reference can force the reader to reread earlier text, especially when the antecedent is an entire sentence. ¹ This distraction can be greater between sentences than within one because the reference spans a longer distance. ² Common triggers in research writing include it, both, this and that. ³ In “We established our assay with a commonly known antibody, and we used it in all subsequent studies”, it could denote either the assay or the antibody; repeating the intended noun removes the ambiguity. ⁴

Four techniques can eliminate personal or demonstrative pronouns that cause backtracking: semantic revision, single syntactic unit revision, double syntactic unit revision and syntactic position revision. ¹ Semantic revision replaces the pronoun with words explicitly identifying its antecedent, using three options. ^{1, 5}

1. An abbreviation: after introducing the Dynamic Marble Size (DMS) algorithm, “The DMS algorithm represents both tasks and resources as agents” replaces an ambiguous “It represents…” without repeating the full name.
2. An attenuated antecedent: “Although this sample survey of current physical therapy outpatients may not translate to the general population, the survey does support development of such a service” replaces it with the shorter the survey.
3. A term renaming the antecedents: after listing infants' decreased engagement in object manipulation, body exploration, midline activities and upper extremity weight-bearing postures, “These decreased engagements may affect neural connectivity” replaces an unclear “This may affect…”.

^{1, 6, 7, 8, 5}

The same abbreviation technique replaces it with VISTA after introducing root coverage by the Vestibular Incisor Subperiosteal Access technique, clarifying that the technique provides the advantages being described. ^{9, 2, 10}

Even an identifiable antecedent can take effort to recover: after two purposes have been described, “both purposes” requires looking back to find them. ^{11, 12} Two repairs are to restate them as an appositive, “both purposes: clarification and resolution”, or to number the purposes in the preceding sentence, forecasting and emphasising them so they are easier to recover. ^{13, 12}

A demonstrative followed by a summarising noun can identify a whole finding: after a sentence reporting that movement frequency was greatest for rotation and least for bodily movement, “That frequency difference was likely due to…” clarifies the referent of “That was likely due to…”. ^{14, 15, 16} A clearly identified antecedent does not always require eliminating the pronoun: in “For the cross-situation, there was a 78% classification rate. That indicated a high degree of consistency for the classification scheme”, the referent of that is clear. ¹⁷

An editing check is to highlight every pronoun and possessive adjective, removing each highlight only after its reference has been checked for clarity. ¹⁸

Sentence reduction and comparison

A clause containing a backtracking pronoun can sometimes become a pronoun-free phrase. ¹⁹ In “In retina, spectrin is bound to retina epithelium, and this results in a different epithelial polarity”, the second clause becomes “resulting in a different epithelial polarity”. ²⁰ In “For Staph aureus, there were discrepancies in the colony count, and that was possibly caused by shortened incubation times or contamination of the culture medium”, it becomes “possibly caused by shortened incubation times or contamination of the culture medium”. ²¹ An infinitive phrase expresses intent, as in test scores being analysed by cluster analysis “to enable identification of subgroups within the sample of girls with AIS”. ^{22, 23, 24}

Reducing both clauses can remove the pronoun and an unnecessary assertion of importance. ^{25, 26, 27} “Timely accurate screening and diagnosis is important because it can reduce the progression of the malignancy” becomes “Timely accurate screening and diagnosis can reduce the progression of the malignancy”. ²⁶ A compound sentence can become a sentence with an appositive: “Lysine is an abundant muscle constituent, and it decreases in amount during starvation” becomes “Lysine, an abundant muscle constituent, decreases in amount during starvation”. ²⁸ The appositive is short enough not to interrupt the flow; a descriptive first clause followed by an assertive second clause, with nonparallel verbs, may indicate that the compound pattern does not suit the intended emphasis. ²⁹

Repositioning compared entities provides another repair. ^{30, 29} “The absolute values for fracture toughness of primary teeth were similar to those for permanent teeth” becomes “The absolute values for fracture toughness were similar between primary and permanent teeth”, eliminating those and avoiding repetition of teeth. ³¹

Backtracking can also arise from adverbs, verbs and nouns that stand in for earlier information. ³² Juxtaposing the corresponding members of two sets avoids making the reader reconstruct their pairing. ³³

Repeated terms

Using synonyms for the same biomedical concept can make a manuscript harder to follow; the most appropriate term for its intended readers should be used consistently, with repeated terms as close together in a paragraph as possible. ^{34, 35} For example, heart muscle contractility and myocardial inotropic state refer to the same concept. ³⁴ Repeating key words and sentence patterns across manuscript sections helps readers and reviewers see similarities and differences. ³⁶ Repeated key words also help link paragraphs and prevent rhetorical tangents. ³⁷

An explicit version of the antecedent, abbreviated or modified to avoid redundancy, can retain continuity without monotonous repetition. ³⁸ Three examples show different forms of this repair. ^{39, 40, 41}

• After introducing post-stroke patients enrolled in a trial, the enrolled patients replaces the participants.
• After composite disks have been cemented to blocks, cemented disks replaces samples, identifying the change in the entity as well as the entity itself.
• After results may have been limited, another limitation replaces another shortcoming, echoing the verb with its noun form.

^{42, 43, 39, 44, 45, 40, 46, 47, 41}

Forecasting and backward references

Forecasting markers tell readers what is coming; backward-reference markers identify information already mentioned, helping maintain continuity in long or complex paragraphs. ^{48, 49} Subheadings can make a shift between dense paragraphs explicit. ^{50, 51} For example, two methods paragraphs describing soil collection and processing followed by chemical analyses gain the run-in subheadings “Collection and processing” and “Chemical analyses”. ^{52, 53, 54, 55}

An end-of-sentence appositive can forecast items discussed in subsequent sentences. ^{56, 57} A paragraph introducing “two essential assistants” for processor performance becomes explicit when the sentence ends “compilers and interconnects among clusters”, naming the subjects of the next two sentences. ^{58, 59, 60, 61}

The definite article the can signal that a noun has already been mentioned and is known to writer and reader. ^{62, 63} After a sentence about infected bone and periodontal tissue, “The infection” adds a backward reference that bare “Infection” lacks, while “Such infection” makes the connection more explicit. ^{64, 65, 66, 67, 61, 68, 69, 70} One proposed ordering of emphasis is such, then this/that, then the. ^{67, 57, 71}

The same marking can connect information across sections. ⁶² Where cell lines have already been introduced, “The three hepatoma cell lines were used in this experiment” signals that prior mention, whereas omitting the makes them appear newly introduced. ^{65, 72, 67, 73, 74, 63} Similarly, “Many of the studies were performed in vitro” refers to previously mentioned studies more explicitly than “Many studies were performed in vitro”. ^{67, 75, 76, 77, 78} Determiners can include articles, indefinite or demonstrative pronouns, and numbers. ⁶³ Forecasting markers help with paragraphs common in materials and methods sections, while backward-reference markers can connect text in any section. ⁷¹

Connectors and their relationships

A conjunctive adverb or adverbial phrase connects clauses or sentences by showing their relationship. ^{79, 80} Meanwhile indicates simultaneous actions or states; back at the ranch signals a change of scene; for example introduces specific instances of a general principle; and however introduces a conflicting or apparently contradictory statement. ⁷⁹ First, second and third can show how supporting sentences relate to a topic sentence. ⁷⁹

A working list of connectors can be classified by function and kept to hand while writing. ⁷⁹ One starter list contains nine groups. ^{79, 81, 82}

Function	Connectors
Addition	furthermore, moreover, in addition, likewise
Apposition	for example, for instance, that is, namely
Cause and effect	consequently, as a result
Concession	nevertheless, however, of course
Contrast	in contrast, rather, on the other hand
Logical relationships	therefore, thus, ergo
Reinforcement	indeed, in fact
Summary	in conclusion, in short
Time	meanwhile, subsequently, thereafter, henceforth

^{79, 81, 82}

Another grouping identifies six common jobs in scientific English: comparison, contrast, chronological order, cause and effect, listing and exemplification. ⁸³ Connectors should be used sparingly rather than repeatedly. ^{83, 84} Repeated moreover can sometimes be varied with furthermore or in addition. ^{85, 84} An already obvious consequence may need no connector: consequently adds nothing in “The pharmacologists determined the pharmacokinetics of the new drug. Consequently, we obtained values for the half-life.” ⁸⁶

The connector should express the intended relationship. ⁷⁹ In the example “An increasing number of patients discontinue their breast cancer treatment despite better hospital management”, despite expresses a contrast and gives the second part a negative connotation. ⁸⁷ In another example, “Doctors are concerned about the rising death rate from asthma despite better hospital management”, placing the concern and rising death rate together links those ideas; despite then contrasts that concern about rising mortality with better management. ^{88, 89, 90}

Therefore marks the conclusion of an argument, not merely the last of several statements of fact. ^{91, 79} In “All men are mortal, and Socrates is a man; therefore, Socrates is mortal”, it tells the reader to accept the final clause because of the first two. ⁹¹ Because can introduce the premises instead, before or after the conclusion. ⁹¹ These markers indicate that an argument may be present, but do not prove it: because can instead explain a cause, and since can indicate time. ⁹² Where time and causation might be confused, because can be clearer than as or since. ^{4, 92}