Multi-word expressions in biomedical abstracts and their plain E nglish adaptations (2024)

Abstract: This study analyzes the use of multi-word expressions (MWEs), prefabricated sequences of words (e.g. in this case, this means that, healthcare service, follow up) in biomedical abstracts and their plain language adaptations. While English academic writing became highly specialized and complex from the late 19th century onwards, recent decades have seen a rising demand for a lay-friendly language in scientific content, especially in the health domain, to bridge a communication gap between experts and laypersons. Based on previous research showing that MWEs are easier to process than non-formulaic word sequences of comparable length, we hypothesize that they can potentially be used to create a more reader-friendly language. Our preliminary results suggest some significant differences between complex and plain abstracts when it comes to the usage patterns and informational load of MWEs.

## introduction previous diachronic research has shown that english scientific writing developed a compressed code of communication that is efficient for its primary users (i.e. scientists) @xcite @xcite . however, the consequence of this process was that academic papers became almost incomprehensible for a general audience, which poses a considerable problem as the need to draw knowledge directly from scientific publications is growing among laypersons, particularly in the health domain. to address this issue, many scholars and journals encourage scientists to use plain language in their papers or at least include plain language summaries of their work @xcite . while writing recommendations on plain language abound, they seem to pay little attention to multi-word expressions (mwes), i.e. prefabricated sequences of several words that are argued to foster the fluency of language use @xcite . our goal is to investigate whether, and if so to what extent mwes can ease the processing of plain language texts. to this end, we analyze the use of mwes in abstracts from biomedical papers ("complex abstracts") and their plain language adaptations ("plain abstracts"). we pose the following questions: (i) does the use of mwes differ in complex and plain abstracts and, more specifically, do plain abstracts use more mwes? (ii) are mwes in plain abstracts easier to process? in general, we expect to see more mwes in plain abstracts. in terms of mwe types, we anticipate that nominal mwes (e.g. compound nouns used as terms), typically associated with technical scientific writing, will be less characteristic of plain abstracts. moreover, we expect mwes in plain abstracts to be less informationally loaded on average (and therefore easier to process). the remainder of the paper is structured as follows. section 2 is dedicated to mwe processing. section 3 describes our data and methodology. in section 4, we present our analysis results. in section 5, we provide a summary and prospects of future work. ## background and related work linguistic studies in recent decades have revealed that mwes make up a large proportion of language use and that they are less costly in processing than other sequences of words @xcite . for instance, @xcite prove that mwes have shorter reading times in comparison to non-formulaic expressions. @xcite and @xcite arrive at similar conclusions using eye-tracking. the assumption about a processing advantage of mwes has also been corroborated by eeg studies (cf. @xcite ). further evidence is pro-vided from speech processing: formulaic expressions are produced faster and more fluently than comparable, non-formulaic expressions and recognized better (e.g. under acoustic degradation; @xcite ). while it now seems increasingly clear that mwes are faster and easier to process than nonformulaic language, what still remains open is whether the use of mwes is influenced by other factors. in register theory, it is widely assumed that speakers adjust their language according to the particular communicative situation @xcite @xcite . one of the parameters describing the communicative situation is the relationship between the speaker and the recipient. for instance, in case of complex abstracts both speaker and recipient have professional knowledge of the subject. in contrast, plain abstracts are written by well-versed speakers for lay recipients. hence, it is plausible to suppose that this shift in the level of expertise should be reflected in the use of mwes, i.e. mwes should be employed in plain abstracts in such a way that reduces the processing cost for the recipient. ## results contrary to what we expected, plain abstracts employ fewer mwes, both in terms of unique occurrences (6,155 vs 6,700) and total frequency (62,976.08 vs 63,802.53 occurrences per million words). compounds are the most common mwe type in both abstract categories as reflected in however, going beyond mere frequency estimations, our kld analysis revealed a considerable difference in the use of mwes in both directions of comparison: 3.35 bits and 3.18 bits for complex vs plain and plain vs complex, respectively. a look at the most distinctive features (see figures 2 and 3 ) also offers interesting insights. while both types of abstracts are characterized by compound mwes to a great extent, we see, for instance, that complex abstracts have more statistical terminology (e.g. confidence interval, mean age, odds ratio etc.) and different research design terms (e.g. cohort study, crossover study, control group etc.). in contrast, such mwes are not encountered among the features distinctive of plain abstracts. this is probably due to the fact that such statistical and methodological information is not relevant for a lay person and, therefore, can be left out to enhance readability. moreover, we see numerous examples of specialized terminology denoting biological and medical phenomena (e.g. dopamine receptor, plasma concentration etc.). since it is impossible to just delete such terms without loosing information relevant to the reader, plain abstracts try to use more common equivalents (e.g. blood sugar levels instead of blood glucose levels). sometimes such transformations lead to the creation of mwes in cases where no mwe is used in complex abstracts. for instance, a one-word term placebo turns into a compound dummy treatment. or an adjective-noun term neurodegenerative disease is replaced with a noun compound brain disorder. other mwe types are also attested among the most characteristic features, albeit marginally. for instance, phrasal verbs seem to be more distinctive of plain abstracts (e.g. find out, make up). fixed and afl mwes are present in both lists, however complex abstracts seem to employ more sophisticated expressions typical of elaborated writing (e.g. as well as, in terms of, according to the etc.). flat mwes are not attested among the most distinctive features. in terms of informativity, as measured by surprisal, we observed significant differences between complex and plain abstracts for compound and afl categories, while phrasal verbs showed a marginally significant difference. 3 all of these three mwe types have lower surprisal for plain abstracts (see figure 4 ), which is, in principle, in line with our expectations although we anticipated a more pronounced trend. lower surprisal values in plain compound mwes might be indicative of mwes being used to effectively reduce processing effort. consider, for instance, the mwe blood glucose levels which is typically used in complex abstracts and has a surprisal of 4.73 bits. its plain language equivalent blood sugar levels, however, transmits 3.24 bits of information on average, thus being easier to process. the same seems to hold for cases where plain abstracts use an mwe instead of a noun with an adjective premodifier, which is a very common terminology formation pattern in scientific texts. compare, for example, the following terms from complex abstracts and their plain language equiv-3 for determining statistical significance we used the wilcoxon rank sum test available in r (r development core team). alents: renal cancer (7.41 bits) vs kidney cancer (5.91 bits) and neurodegenerative disease (12.20 bits) vs brain disorder (3.65 bits). a similar mechanism seems to apply to phrasal verb mwes that can be used as an alternative to more complex verbs. consider, for instance, example (1) extracted from a complex abstract and its plain language adaptation shown in example (2) (values in parenthesis indicate surprisal in the corresponding sentence) (1) while in general our findings do suggest that some types of mwes per se seem to be easier to process in plain language abstracts, a more indepth analysis is needed to investigate how rewrit-ing strategies like those described above affect processing complexity on the sentence and text level. ## conclusion and future work in this study, we investigated mwes in biomedical abstracts and their plain language adaptations. we were able to establish some differences in the use of mwes (e.g. more prominent use of statistical and methodological terms in complex abstracts, greater reliance on phrasal verbs in plain abstracts). furthermore, we found that the informational load of compound, phrasal verb and afl mwes is lower in plain abstracts, suggesting that the use of mwes might play a role in decreasing processing cost in the transition from complex to plain language. in future studies, we will focus on the mwe types individually to investigate why plain mwes have lower surprisal. additionally, we are planning to expand our methodology to account for factors that might be correlated with the mwe processing cost (e.g. association strength among the component parts of an mwe).