Received 3 March 2016; accepted 10 April 2016; published 13 April 2016
Scientific discourse contains unique grammatical structures that construe scientific knowledge and reshape human experience (Halliday, 1994; Halliday & Matthiessen, 1999) . Studies analyzing the distinctive features of scientific discourse (e.g. Hyland, 1998, 2001, 2002; Hyland & Tse, 2004; Swales, 1990, 2004 ) and the possible impact of language or discipline (e.g. Bazerman, 1985, 1988; Breivega et al., 2002; Dahl, 2004; Duszak, 1994; Mauranen, 1993; Moreno, 2004 ) have revealed that scientific language reflects the culture of the discourse community. To be precise, the cultural and social norms affect the way scientists reflect their world and the ways they develop logical reasoning. Each discourse community “employs its institutional discourse, its way of describing and categorizing a problem” (Reeves, 2005: p. 99) . Taking this view, a large number of studies have been carried out on the research article (RA) focusing on its rhetorical and lexico-grammatical features (e.g. Hyland, 1996, 1999; Yakhontova, 2002; Chang & Schleppegrell, 2011 ).
1.1. Stance in Academic Discourse
The concept of stance has been examined by different researchers under different terms and definitions. Stance is defined as “a textual voice”, conveying the attitudinal manner of the writer (Hyland, 2001: p. 176) . Similarly, Conrad and Biber (2000) identifies stance as attitudinal stance which reflects the writer’s attitude towards an issue, event, or person. Thus, authorial stance presents writers’ viewpoints on the components of their work they introduce. Biber (1988) describes stance as “the ways in which an author or speaker overtly expresses attitudes, feelings, judgments, or commitment concerning the message” (p. 204). In other words, linguistic expressions of stance serve to convey how certain the writers feel and also what perspective they take towards a proposition (Biber, 2006) . In this respect, Jaffe (2009) points out that taking a stance is observed in every human communication and even establishing a neutral point of view is evidence of stance. Considering the importance of stance, Hyland (2005) proposes a set of concepts in the process of examining stance-taking. These concepts are evidentiality, hedging and boosters.
Research on academic discourse has also shown that soft science and hard science writers interact differently with their readers (Hyland, 1998, 2001) . Soft sciences comprise disciplines such as psychology, sociology, linguistics and political sciences and are also called social sciences. Hard sciences, on the other hand, include disciplines such as physics, chemistry and biology and they are labeled as physical or natural sciences. Becher (1989) maintains that knowledge production in soft and hard sciences is carried out differently. While writers in hard sciences reveal objectivity, authors in soft sciences demonstrate greater subjectivity. Thus, there is an impersonalized voice in hard sciences and a personalized stance in the soft sciences.
1.2. Stance Adverbs as the Grammatical Expression of Stance
Stance adverbs are widely used in academic discourse, and “speakers use stance adverbs to convey their judgments and attitudes, to claim the factual nature of what they are saying, and to mark exactly how they mean their utterances to be understood” (Biber et al., 1999: pp. 766-767) . Stance adverbs have been studied exclusively or together with other linguistic expressions within the fields of discourse analysis (Hoye, 1997; Stubbs, 1986) hedging (Hyland, 1998) mitigation (Fraser, 1980; Holmes, 1984) evidentiality (Chafe, 1986) evaluation (Hunston & Thompson, 2000) appraisal (Martin & White, 2005) . In particular, studies carried out by Biber and Finegan (1988, 1989) , and Fraser (1996) among others, have specifically focused on stance adverbs. The classifications proposed in all these studies, however, do not overlap and the adverbs are studied under various labels such as “disjuncts”, “adjuncts”, and “markers”.
The classification of adverbs reflecting stance proposed by Biber (2006) were used to analyze the stance adverbs of academic writers in this study. As shown in Figure 1, Biber et al. (1999) and Biber (2006) distinguish four main types of stance adverbs namely: epistemic adverbs (certainty adverbs, likelihood adverbs), attitude adverbs and style adverbs. Epistemic adverbs present the speaker’s comments about the status of information in a proposition and indicate the certainty or doubt. In this group, certainty adverbs denote that the writer commits him/herself to the truth of the proposition expressed in the utterance. Thus, by using acertainty adverb, the writer asserts the truth of the proposition. In contrast, likelihood adverbs are used when the writer makes judgment on the truth value of the proposition and usually indicate a doubt. Attitude adverbs report personal attitudes or feelings. Style adverbs, on the other hand, indicate comments on the communication itself (Biber et al., 1999: pp. 972-975) . Style adverbs are employed to comment on the manner of presenting information. They are usually used to strengthen the truth-value of a proposition or claim (Hinkel, 2003) .
Even though I have employedthe classification of stance adverbs of Biber et al. (1999) for exploring the linguistic realization of stance, I have departed from it in some respect. First, I look at single word adverbs alone. Secondly, underepistemic adverbs I include also domain adverbs such as biologically, chemically, theoretically. Domain adverbs are also among lexico-grammatical features conveying stance and projecting evaluations. These adverbs reflect comments conveying commitment to the propositional content. By specifying a field within a
proposition, the writer signals that the degree of probability of the proposition is the highest (Tseronis, 2009: p. 59) .
・ Are there any similarities/differences in the use of stance adverbs in the soft and hard sciences?
2.1. Construction of Subcorpora
Table 1. Descriptive information on the subcorpora.
Table 2. Number of words in the corpus.
2.2. Data Analysis
3.1. Total Number of Adverbs
3.2. Distribution of Adverbs in Hard and Soft Sciences
Figure 2. Raw numbers of adverbs used by native and non-native writers.
Figure 3. Distribution of stance adverbs across hard and soft sciences.
0.221 > 0.05), domain adverbs (p = 0.952 > 0.05), attitude adverbs (p = 0.099 > 0.05), and style adverbs (p = 0.349 > 0.05) in soft and hard sciences, but the difference in the total number of stance adverbs between soft sciences and hard sciences was statistically significant (p = 0.003 < 0.05).
3.3. Distribution of Adverbs across Six Disciplines
Frequency of stance adverbs in each discipline was small, thus formal statistical analysis could not be applied separately on each discipline. However, raw numbers of the frequency of adverbs in each discipline are given in Figure 4 to provide a general picture of how frequently stance adverbs were employed across different disciplines. Disciplinary differences were also found in terms of the distribution of stance adverbs. Disciplines representing the social sciences showed a higher frequency of adverbs. Figure 4 summarizes the results of the frequency distribution of stance adverbs across disciplines.
Figure 4. Use of stance adverbs across six disciplines.
In response to the second research question, i.e., whether there were differences in the use of stance adverbs between soft and hard sciences, the results demonstrated that the frequency of stance adverbs was higher in the soft sciences than in hard sciences. This phenomenon seems to indicate that hard sciences and soft sciences use different strategies in presenting scientific meaning. While the hard sciences tends to build knowledge on the basis of experimental observation and evidence, soft sciences seeks for alternative ways to construct scientific knowledge. Thus, in social sciences the academic writer has to draw on different linguistic devices for reasoning and validating his/her point of view. In this respect, disciplines representing the social sciences displayed a higher frequency of stance adverbs. From these results, it can be concluded that there might be different disciplinary norms for using lexico-grammatical features like stance adverbs across disciplines. These findings are in line with previous research (Samraj, 2002; Stotesbury, 2003; Yakhontova, 2006; Çakır, 2011) comparing disciplines.
Although these limitations show that this research is far from finished, it can help academic writers understand how they construct stance in their writing. Learning the features of academic discourse can help writers understand how language works in any academic setting. This type of awareness would give academic writers a repertoire of voices that they would be able to choose from depending on the type of writing they needed to create and could help them integrate better into the academic community.
The overall results obtained in this study suggest that there are obvious differences between the use of stance adverbs by native writers and non-native Turkish writers.
Although much remains to be done to better understand the linguistic resources that convey stance, this study tried to shed some lights into how non-native and native writers use stance adverbs to construe their stance and comment on their research. Further studies are needed to verify the role of grammatical expressions on authorial stance in academic discourse.
*This article is a revised version of a paper presented at the Akdeniz Language Studies Conference.
 Ahmad, U., & Mehrjooseresht, M. (2012). Stance Adverbials in Engineering Theses Abstracts. Procedia-Social and Behavioral Sciences, 66, 29-36.
 Akbas, E. (2012a). Exploring Meta-discourse in Master’s Dissertation Abstracts: Cultural and Linguistic Variations across Postgraduate Writers. International Journal of Applied Linguistics and English Literature, 1, 12-26.
 Akbas, E. (2014). Are They Discussing in the Same Way? Interactional Metadiscourse in Turkish Writers’ Texts. In A. Lyda, & K. Warchal (Eds.), Occupying Niches: Interculturality, Cross-Culturality and Aculturality in Academic Research (pp. 119-133). London/Berlin: Springer.
 Bachschmidt, P. (1999). Construction de l’argumantation dans l’article de recherché en méchanique, differences entre discourse du francophone et de l’anglophone. Asp, 23-26, 197-207.
 Bayyurt, Y., & Akbas, E. (2014). Akademik metinlerde Kacinma ve Vurgulayici Ifadelerin Lisansüstü Ogrenciler Tarafindan Algilanmasi ve Kullanilmasi (Graduate Students’ Perception and Use of Hedges and Boosters in Academic Texts). Ulusal Dilbilim Kurultayi Bildirileri. Ankara: Hacettepe üniversitesi Yayinlari.
 Bazerman, C. (1985). Physicists Reading Physics—Schema-Laden Purposes and Purpose Laden Schema. Written Communication, 2, 1.
 Biber, D. (1988). Variation across Speech and Writing. Cambridge: Cambridge University Press.
 Biber, D. (2006). University Language: A Corpus-Based Study of Spoken and Written Registers. Amsterdam/Philadelphia: John Benjamins.
 Biber, D., & Finegan, E. (1988). Adverbial Stance Types in English. Discourse Processes, 11, 1-34.
 Biber, D., & Finegan, E. (1989). Styles of Stance in English: Lexical and Grammatical Marking of Evidentiality and Affect. Text, 9, 93-124.
 Breivega, K. R., Dahl, T., & Flottum, K. (2002). Traces of Self and Others in Research Articles: A Comparative Pilot Study of English, French and Norwegian Research Articles in Medicine, Economics and Linguistics. Applied Linguistics, 12, 218-239.
 Cakir, H. (2011). Türkce ve Ingilizce Bilimsel Makale Ozetlerinde Bilgiyi Kurgulama ve Yazar Kimligini Kodlama Bicimleri (Forms of Constructing Scientific Knowledge and Encoding Writer’s Stance in Turkish and English Research Article Abstracts). Unpublished Doctoral Dissertation, Izmir: Dokuz Eylül University.
 Cakir, H., & Fidan, O. (2015). A Contrastive Study of the Rhetorical Structure of Turkish and English Research Article Abstracts. In D. Zeyrek, C. Sagin Simsek, U. Atas, & J. Rehbein (Eds.), Ankara Papers in Turkish and Turkic Linguistics (pp. 367-378). Wiesbaden: Harrassowitz Verlag.
 Cakir, H., & Kansu Yetkiner, N. (2012). Information Packaging in Scientific Discourse Across Disciplines and Languages: Explicitation Hypothesis in Translation Studies Revisited. Paper presented at the International Language, Literature and Stylistics Symposium, Edirne: Trakya University.
 Candarli, D. (2012). A Cross-Cultural Investigation of English and Turkish Research Article Abstracts in Educational Sciences. Studies about Languages, 20, 12-17.
 Chafe, W.L. (1986). Evidentiality in English Conversation and Academic Writing. In W. L. Chafe, & J. Nichols (Eds.), Evidentiality: The Linguistic Coding of Epistemology (pp. 261-272). Norwood, NJ: Ablex.
 Chang, P., & Schleppegrell, M. J. (2011). Taking an Effective Authorial Stance in Academic Writing: Making the Linguistic Resources Explicit for L2 Writers in the Social Sciences. Journal of English for Academic Purposes, 10, 140-151.
 Conrad, S., & Biber, D. (2000). Adverbial Marking of Stance in Speech and Writing. In S. Hunston, & G. Thompson (Eds.), Evaluation in Text: Authorial Stance and the Construction of Discourse (pp. 56-73). Oxford: Oxford University Press.
 Cross, C., & Oppenheim, C. (2006). A Genre Analysis of Scientific Abstracts. Journal of Documentation, 62, 428-446.
 Dahl, T. (2004). Textual Metadiscourse in Research Articles: A Marker of National Culture or of Academic Discipline. Journal of Pragmatics, 36, 1807-1825.
 Duszak, A. (1994). Academic Discourse and Intellectual Styles. Journal of Pragmatics, 21, 291-313.
 Fidan, O., & Cakir, H. (2012). The Use of Verbs in Turkish and English Research Article Abstracts. Paper presented at the International Language, Literature and Stylistics Symposium, Edirne: Trakya University.
 Fraser, B. (1980). Conversational Mitigation. Journal of Pragmatics, 4, 341-350.
 Fraser, B. (1996). Pragmatic Markers. Pragmatics, 6, 167-190.
 Galebiowski, Z. (2009). Prominent Messages in Education and Applied Linguistic Abstracts: How Do Authors Appeal to their Prospective Reader? Journal of Pragmatics, 41, 753-769.
 Getkham, K. (2016). Authorial Stance in Thai Students’ Doctoral Dissertation. English Language Education, 9, 80-95.
 Graetz, N. (1985). Teaching EFL Students to Extract Structural Information from Abstracts. In J. M. Ulign, & A. K. Pugh (Eds.), Reading for Professional Purposes: Methods and Materials in Teaching Languages (pp. 123-135). Leuven: Acco.
 Hinkel, E. (2003). Adverbial Markers and Tone in L1 and L2 Students’ Writing. Journal of Pragmatics, 35, 1049-1068.
 Holmes, J. (1984). Modifying Illocutionary Force. Journal of Pragmatics, 8, 345-365.
 Huber, E., & Uzun, L. S. (2000). Dilbilim alaninda Türkce yazilan bilimsel metinler üzerine gozlemler (Observations on Scientific Texts Written in Turkish in Linguistics). In S. Ozsoy, & E. E. Taylan (Eds.), 2000. XIII. Dilbilim Kurultayi Bildirileri (pp. 201-215). Istanbul: Bogazici üniversitesi Yayinlari.
 Hyland, K. (1996). Writing without Conviction: Hedging in Science Research Articles. Applied Linguistics, 17, 433-454.
 Hyland, K. (1998). Hedging in Scientific Research Articles. Amsterdam: John Benjamins.
 Hyland, K. (2001). Bringing in the Reader: Addressee Features in Academic Writing. Written Communication, 18, 549-574.
 Hyland, K. (2002). Authority and Invisibility: Authorial Identity in Academic Writing. Journal of Pragmatics, 34, 1091-1112.
 Hyland, K. (2005). Stance and Engagement: A Model of Interaction in Academic Discourse. Discourse Studies, 7, 173-192.
 Hyland, K., & Tse, P. (2004). Metadiscourse in Academic Writing: A Reappraisal. Applied Linguistics, 25, 156-177.
 Hyland, K., & Tse, P. (2005). Hooking the Reader: A Corpus Study of Evaluative That in Abstracts. English for Specific Purposes, 24, 123-139.
 Jaffe, A. (2009). Stance: Sociolinguistic Perspectives. Oxford: Oxford University Press.
 Kafes, H. (2009). Authorial Stance in Academic English: Native and Non-Native Academic Speaker Writers’ Use of Stance Devices (Modal Verbs) in Research Articles. Unpublished Dissertation, Eskisehir: Anadolu University.
 Kavanoz, S., & Simsek, S. (2013). Egitim Bilimleri Arastirma Makalelerine Tür-Odakli Yaklasim: Karsilastirmali Cozümleme (A Genre-Based Approach to Research Articles in Educational Sciences: Comparative Analysis). Turkish Studies, 8, 693-710.
 Lorés, R. (2004). On RA Abstracts: From Rhetorical Structure to Thematic Organisation. English for Specific Purposes, 23, 280-302.
 Martín-Martín P. (2002). A Genre Analysis of English and Spanish Research Paper Abstracts in Experimental Social Sciences. English for Specific Purposes, 22, 25-43.
 Martín-Martín, P., & Burgess, S. (2004). The Rhetorical Management of Academic Criticism in Research Article Abstracts. Text, 24, 171-195.
 Mauranen, A. (1993). Contrastive ESP Rhetoric: Metatext in Finnish-English Economic Texts. English for Specific Purposes, 12, 3-22.
 Melander, B., Swales, J. M., & Fredrickson, K. M. (1997). Journal Abstracts from Three Academic Fields in the United States and Sweden: National or Disciplinary Proclivities? In A. Duszak (Ed.), Culture and Styles of Academic Discourse (pp. 251-272). Berlin: Mouton De Gruyter.
 Moreno, A. (2004). Retrospective Labelling in Premise-Conclusion Metatext: An English-Spanish Contrastive Study of Research Articles on Business and Economics. Journal of English Academic Purpose, 3, 321-339.
 Onder Ozdemir, N., & Longo, B. (2014). Metadiscourse Use in Thesis Abstracts: A Cross-Cultural Study. Procedia-Social and Behavioral Sciences, 141, 59-63.
 Régent. O. (1985). A Comparative Approach to the Learning of Specialized Written Discourse. In P. Riley (Ed.), Discourse and Learning: Paper in Applied Linguistics and Language Learning from the Centre de Recherches et d’Applications Pédagoques en Languages (pp. 105-120). New York: Longman.
 Salager-Meyer, F. (1992). A Text-Type and Move Analysis Study of Verb Tense and Modality Distribution in Medical English Abstracts. English for Specific Purposes, 11, 93-113.
 Santos, M. B. D. (1996). The Textual Organization of Research Paper Abstracts in Applied Linguistics. Text, 16, 481-499.
 Silver, M. (2003). The Stance of Stance: A Critical Look at Ways Stance Is Expressed and Modeled in Academic Discourse. Journal of English for Academic Purposes, 2, 359-374.
 Stotesbury, H. (2003). Evaluation in Research Article Ab-stracts in the Narrative and Hard Sciences. Journal of English for Academic Purposes, 2, 327-341.
 Stubbs, M. (1986). “A Matter of Prolonged Fieldwork”: Notes towards a Modalgrammar of English. Applied Linguistics, 7, 1-25.
 Swales, J. (2004). Research Genres. Cambridge: Cambridge University Press.
 ülker Eser, M. (2012). A Comparative Analysis of Thesis Guidelines and Master Thesis Abstracts Written in English at Univer-sities in Turkey and in the USA. Unpublished MA Thesis, Ankara: Middle East Technical University.
 Uysal H. H., & Akpinar, K. D. (2008). Cross-Cultural Differences in Turkish, Japanese and Indian Scholars’ Conference Abstracts. The 8th International Language, Literature, and Stylistics Conference, Izmir.
 Uysal, H. H. (2014). A Cross-Cultural Study of Indirectness and Hedging in the Conference Proposals of English NS and NNS Scholars. In A. Lyda, & K. Warchal (Eds.), Occupying Niches: Interculturality, Cross-Culturality and Aculturality in Academic Research (pp. 179-195). Switzerland: Springer International Publishing.
 Van Bonn, S., & Swales, J. M. (2007). English and French Journal Abstracts in the Language Sciences: Three Exploratory Studies. Journal of English for Academic Purposes, 6, 93-108.
 Ventola, E. (1994). Abstracts as an Object of Linguistic Study. In S. Cmejrkova, F. Danes, & E. Havlova (Eds.), Writing vs. Speaking. Language, Text, Discourse, Communication (pp. 333-352). Tübingen: Gunter Narr.
 Yagiz, O., & Demir, C. (2014). Hedging Strategies in Academic Discourse: A Comparative Analysis of Turkish Writers and Native Writers of English. Procedia-Social and Behavioral Sciences, 158, 260-268.
 Yakhontova, T. (2006). Cultural and Disciplinary Variation in Academic Discourse: The Issue of Influencing Factors. Journal of English for Academic Purposes, 5, 153-167.