The emerging importance of multi-word expressions has aroused researchers’
interest in investigating various types of recurrent word co-occurrence in academic prose based on corpus data (e.g. Biber, Conrad, & Cortes, 2004; Chen & Baker, 2010;
Hyland, 2008). Nevertheless, the exploration of academic collocations begins comparatively late, and less robust, compared to the investigations of other types of multi-word units (e.g. lexical bundles). Efforts of compiling an academic collocation list for EAP teaching/learning are even scanter. To the researcher’s best knowledge, the systematic compilation of academic collocation lists have been recently undertaken by Durrant in 2009 and Ackermann & Chen in 2013, both of which drew on corpus data across different academic disciplines to develop an academic collocation list.
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2.1.1 Durrant’s Academic Collocation List
Durrant (2009) compiled an academic collocation list based on a 25-million-word corpus, which includes 3,251 research articles of 31 academic schools across five disciplines (i.e. Arts and Humanities, Life Sciences, Science and Engineering, Social-Administrative, and Social-Psychological). To retrieve his list of academic collocations, Durrant first extracted keywords from different schools, and further identified high-frequency collocations based on these keywords. In his list of high-high-frequency collocations, it was found that over 76% (n=763) of the top 1,000 collocations were grammatical collocations, such as this study and associated with. He claims that frequent grammatical collocations like these are so commonly seen in academic English that they should be introduced to English learners.
While Durrant argued strongly that many of his grammatical collocations possess great value for English learners, he also admitted that this finding “may be a disappointment to some” and that “such items [grammatical collocations] are not what many teachers have in mind when they think of collocations (p.163).” Indeed, to many researchers and language teachers, lexical collocations (e.g. ‘conduct a study’ and
‘significant difference’) are usually the more valuable phraseological units worthy of further investigation (e.g. Granger, 1998; Laufer & Waldman, 2011; Nesselhauf, 2003).
The combination of two open-class components are also the main targets included in most of the collocation dictionaries, such as Oxford Collocations Dictionary for Students of English and Macmillan Collocations Dictionary. Ackermann and Chen (2013) also comment that Durrant’s listing “does not provide readily usable materials for EAP teaching and learning (p.236)”, even though his listing might revealed some patterns (i.e., grammatical collocations) overlooked by researchers.
Although collocations identified in Durrant’s study are considered less usable, the
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results of his research still yielded some interesting findings regarding the disciplinary differences in writers’ collocation use. In the retrieval of keywords, Durrant already discovered a huge gap between disciplines in the Arts and Humanities and those in other groups. Between the 26 schools outside of Arts and Humanities, the mean percentage of overlapped keywords was 26%; however, the percentage drastically dropped to 20%
when the schools of Arts and Humanities were included. This disciplinary gap was also observed in the total frequency of key collocations for the Arts and Humanities groups.
For all the other academic schools, the frequency of key collocations was within a relatively narrow band of 30-35,000 per-million-words (PMWs), whereas the rate for the groupings of Arts and Humanities decreased to 17,677 PMWs. Based on these findings, Durrant concluded that the vocabulary needs of students in the Arts and Humanities are substantially different from those in other disciplines and “should be treated separately (p.165).”
2.1.2 Ackermann and Chen’s Academic Collocation List
The divergence of collocation use in different disciplines exists not only in Durrant’s listing of grammatical collocations, but in Ackermann and Chen’s listing (2013) of academic lexical collocations as well. Adopting a mixed approach of both automated extraction and expert judgment, Ackermann and Chen identified 2,468 lexical collocations of four major types in the 25.6-million-word written curricular component of Pearson International Corpus of Academic English (PICAE), which consists of journal articles and textbook chapters in the fields of Applied Sciences and Professions, Humanities, Social Science, and Natural/Formal Sciences. Although the researchers’ original aim was to generate an academic collocation list for all EAP students, some example items presented in their study still suggested disciplinary difference between the uses of collocations in different fields. For instance, the
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researchers observed that, in the field of Humanities, some combinations (e.g.
‘academic writing’ and ‘make explicit’) appeared more frequently than in the other three fields, whereas some (e.g. ‘economic growth’ and ‘adversely affect’) occurred less often in the field of Humanities (see Table 2.1 for more examples). The uneven frequency of these items again demonstrated that the use of academic collocation in one academic field might be drastically different from that in others.
Table 2.1. Normed Frequency per Million Word of Example Collocations Selected from Ackermann and Chen (2013).
In addition to disciplinary difference, Ackermann and Chen’s (2013) listing also revealed the preferred use of noun-related combinations in written academic register.
As illustrated in Figure 2.1, noun combinations (i.e. adjective-noun and noun-noun) formed the largest group of lexical collocations, accounting for 74.3% (n=1,835) of the 2,468 entries. The second largest group were verb combinations with nouns or adjectives as complements (13.8%, n=340). The remaining two combination types were
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verb-adverb combinations (6.9%, n=170) and adverb-adjective combinations (5.0%, n=124). The researchers suggested that the dominance of nominal combinations in their list reflects the feature of nominalization in academic texts, and proposed that the great tendency of collocating nouns with other word classes requires more investigations.
Figure 2.1. Overview of Final Academic Collocations in Part-of-Speech Combinations (Source: Ackermann & Chen, 2013).
2.1.3 The Proposed List: A Discipline-specific Verb-Noun and Adjective-Noun Academic Collocation List
Both Durrant’s (2009) and Ackermann & Chen’s (2013) studies listed some useful collocations for EAP teaching/learning; however, it is questionable to claim that the two lists are indeed feasible for all students. As mentioned in previous section, the majority of Durrant’s listing consisted of grammatical collocations, the teaching/learning values of which are often considered less high as compared to lexical collocations. For better EAP teaching/learning, the compilation of lexical collocations should be carried out prior to grammatical collocations. In addition, both of the two lists demonstrated that
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different academic fields prefer different combinations, and that this disciplinary difference is consistently observable in the field of Arts and Humanities. This discovery implies that, at least for students in Humanities, a collocation list generated from texts produced by writers in this field will benefit them more than a list consisting items retrieved across different disciplines.
The present study thus proposed to generate a discipline-specific verb-noun and adjective-noun collocation list for students in the field of applied linguistics. The reason for choosing applied linguistics as the target discipline is that, for many students in this field, producing English academic articles is a common practice in their academic life.
An academic collocation list is thus necessary to enhance their English writing ability.
In addition, (applied) linguistics belongs to the sub-category of Humanities in both Durrant (2009) and Ackermann & Chen (2013), which was discovered to be highly divergent from other disciplines in terms of collocation use. The field of applied linguistics is thus a great area for further investigation.
Regarding the types of lexical combination investigated, the researcher targeted on verb + noun combinations and adjective- noun combinations in the present study. In Ackermann and Chen’s study (2013), the noun combination group, including adjective-noun and adjective-noun-adjective-noun combinations, formed a high proportion of all combinations, whereas verb-noun combinations fall into the second largest group. However, a closer examination on the proportion of each individual type revealed that, while adjective- noun combinations still made up the largest proportion of all types (71.8%, n=1,773), noun-noun combinations only formed a small proportion (2.5%, n=62). Instead, verb-noun combinations accounted for 12.6% (n=310), ranking the second largest type of all.
The proportion of adjective-noun and verb-noun combinations together formed a significant high proportion (84.4%) of all. It seems that verb-noun and adjective-noun
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combinations serve as the core collocation types in academic writing. In addition, past research on ESL/EFL learners’ collocation use also suggests that these two collocation types are difficult for learners to master (see Section 2.2 for detailed discussion). The researchers thus decided to investigate only adjective-noun and verb-noun combinations in the present study, examining how adjective-noun and verb-noun collocations are employed in the field of applied linguistics.