A Contrastive Study of Theme Types in Academic IELTS Essays Written by English-Majored Students and IELTS Candidates

The present study was conducted to investigate theme types in academic IELTS essays written by successful test-takers and English-majored students at Quang Nam university, applying Halliday (2014)’s functional model of Theme-Rheme in English, and then making a comparison between two different levels of performance: one with 7-7.5 band scores and the other written by English-majored students to identify similarities and differences between two essay groups. In this study, the data were 60 IELTS essays collected from two domains: 30 IELTS essays written by English majored students at Quang Nam university, and 30 sample essays scored from 7.0 to 7.5. The findings of this study are expected to enable IELTS test-takers in general and English-majored students at Quang Nam university in particular to take into account the prominent theme types of academic IELTS sample essays in order to make good use of thematic strategies to produce an effective and coherent piece of writing

has attracted great attention of language researchers and teachers in different countries where English is taught as a foreign language or second language.
It is widely believed that profound understanding of thematic progression will provide insights into not only the meaning but also the function of a text or a discourse for the purpose of achieving communicative effects.As Halliday & Matthiessen (2014, p. 133) states, "…by analyzing the thematic structure of a text clause by clause, we can gain an insight into its texture and understand how the writer made clear to us the nature of his underlying concerns."Accordingly, this study attempts to identify what elements in an English clause are selected as Themes in successful IELTS sample essays and essays written by English-majored students at Quang Nam university in the light of functional grammar, and then making a comparison between two different levels of performance in order to find out similarities and differences between two essay groups.The findings of this study are expected to enable IELTS test-takers in general and English-majored students at Quang Nam university in particular to take into account the prominent types of Themes employed in academic IELTS sample essays, whereby they can make good use of thematic strategies to produce an effective and coherent academic IELTS essays.

Previous Studies
Thematic progression represents the way of developing themes and rhemes in clauses, which is of great significance in text cohesion and coherence.Ebrahimi & Ebrahimi (2014) confirmed that Theme-Rheme occupies a crucial role in text cohesion and coherence as it first "enhances connectivity between ideas" and second "guides the readers through the logical paths constructed by the writers".Over the past few years, thematic progression has drawn increasing attention from language researchers and educators such as Garvin (1964), Danes (1974), Brown and Yule (1983), McCarthy (1991), Firbas (1992), Berry (1995Berry ( , 1996)), McCabe (1999), Green et al. (2000), Bloor & Bloor, 2003;McCabe, 1999, Belmonte andMcCabe (2001), Halliday (1985Halliday ( , 1994)), and Halliday andMatthiessen (2004, 2014).There has been a growing amount of practical studies related to Theme-Rheme in academic writing in the past few years.For example, Rakhman (2013) used Eggins (2004) and Danes (1974)' classification of thematic patterns to analyze students' exposition texts and found that the students used simple linear theme progression, constant theme progression and derived thematic progression in order to make their piece of writing coherent, and middle and high achievers' texts were consistent with the argumentative language features thanks to their more deployment of derived theme progression, simple linear theme progression than constant theme progression.
Linda and Ratna (2014) examined thematic progression deployed in EFL students' writing using interviews, classroom observations, and a review of the students' written works and discovered that there remained a number of problems, namely less varied utilization of themes, and over-use of constant thematic pattern.From the findings, Linda proposed to have students expand on the text by adding simple linear development and affirmed that thematic progression might be a useful tool for teachers to assess students' written work.
Contributing to the picture of the importance of thematic progression in writing is the study conducted by Nurdianingsih and Purnama's (2017) on the effect of thematic progression pattern in experimental class and control class.The findings indicated that thematic progression pattern had an effective influence on writing in terms of organization.Syharizal et al. (2018) analyzed thematic progression in students' writing based on Bloor and Bloor (2018)'s framework to find out which types of thematic progression the students used most in their written texts.Their findings showed that the most popular thematic progression used in the students' writing was constant theme pattern because the students found it easy to use this kind of pattern.However, the researchers merely focused on the analysis and draw conclusions without providing any recommendations.
In a similar vein, Darmila et al. (2019) examined thematic progression and stated that three kinds of thematic progression, namely simple linear progression, constant theme progression and derived theme progression were employed by the students to organize their ideas logically in discussion essays.However, they still had weaknesses in developing their ideas with logical justifications and overused constant thematic progression.Khalifa (2020) undertook an investigation into theme choices in academic essays written by Libyan students.The findings indicated that topical unmarked themes were the most popular, followed by textual themes while interpersonal themes were rarely employed in the students' essays.In the light of the study results, the researcher suggested that teachers should take theme selection into consideration in teaching writing and provide students with explicit instructions as well as show them how to create a coherent piece of writing with specific examples of themes.
In an attempt to find out students' problems in arranging the information in their writing, Al-Otaibe (2021) analyzed students' argumentative essays based on Halliday (2004)'s theory of Theme-Rheme and found that students did not produce a coherent writing due to the problem of brand new theme, empty theme, confusing selection of textual theme, and empty rheme.From the findings, the researcher recommended that students should be exposed to authentic texts to examine and to practice analysis of thematic progression and analysis of the use of theme and rheme to improve their writing abilities.
The most recent study, "Thematic development in students' argumentative essay', in Journal of Language Teaching and Learning, Linguistics and Literature conducted by Sari and Agustina (2022) analyzed thematic development proposed by Eggins (2004)'s theory and found that the most frequently used thematic patterns in the students' argumentative essays was theme reiteration, followed by zig-zag pattern, while multiple theme pattern was the least common.The study also confirmed the crucial role of thematic development in making the text coherent and cohesive.
It can be inferred from the reviewed literature that most of the studies mentioned above provide insights into Theme-Rheme.However, to the best of our knowledge, the number of studies dealing with theme choice in students' writing performance is still limited.The study is, therefore, to investigate types of themes in both groups: the 7-7.5 band score essays and English-majored students' essays in the light of SFL in order to examine prominent types of theme of high-quality academic IELTS sample essays and differences between high scoring and low-scoring essays in terms of theme selection, thereby making significant methodological and practical contributions to achieve success in IELTS writing essays.

Theoretical Background 2.2.1. Academic IELTS Writing
Task 2 essay of the IELTS academic test requires candidates to discuss an argument, opinion or point of view.Candidates may be asked to write about common topics which are easily understandable, including education, environment, technology, health, sociology, government spending, and culture.In academic IELTS writing Task 2, candidates are required to write a 250-word essay presenting an argument on a given topic.They are advised to spend about 40 minutes on Task 2, which is worth twice as many marks as Task 1.
In academic IELTS writing, candidates are assessed on their performance according to four criteria, namely Task response, Coherence and cohesion, Lexical resource, and Grammatical range and accuracy described in detailed performance descriptors at the 9 IELTS bands.
Task response: this criterion pertains to the candidate's ability to formulate and develop a stance concerning a question or statement.Arguments should be supported by evidence, and the candidate's personal experiences may be used as examples.The length of responses must be at least 250 words.
Coherence and cohesion: this criterion relates to overall clarity and fluency of the message: how logical the ideas are presented and how well the ideas are linked together by varied and appropriate use of cohesive devices.
Lexical resource: this criterion refers to the range of vocabulary the candidate uses and the precision and appropriacy of that use.
Grammatical range and accuracy: this criterion is connected with the range and accurate use of the candidate's grammatical resource at sentence level.

Themes
Halliday, the founder of systemic functional linguistics, claimed that "Theme in a clause is the element which serves as the point of departure of the message, it is that with which the clause is concerned, while Rheme is the part of the clause in which the Theme is developed" (Halliday, 1994, p. 37).According to Thompson (2004, p. 143), "The Theme of a clause is the first constituent of the clause.All the rest of the clause is simply labelled the Rheme." This study adopts the definition of Halliday and Matthiessen (2014), which posits that theme is "the point of departure of the message".Rheme, meanwhile, is the "remainder of the message, the part in which the Theme is developed" (Halliday & Matthiessen, 2014, p. 89).

Marked and Unmarked Theme
It is easy to distinguish between theme and rheme.Theme is the first element occurring in a clause; the remainder of clause is rheme.The following is an example of Theme-Rheme provided by Halliday & Matthiessen (2014, p. 100).
Theme Rheme (1) London Bridge is fallen down ( 2) Merrily we roll along The Theme 'London Bridge' in the first example conflated with the grammatical subject of the clause, as can be observed from the above division of theme and rheme in the clause.Halliday (2014) refers to this kind of theme as unmarked theme.Marked theme, on the other hand, is something other than the subject namely adjunct and complement like in the second clause, where the adverbial group 'merrily', is the theme.Therefore, theme may be realized by an adverbial group, a prepositional phrase, a nominal group, or a dependent clause.

Topical, Textual and Interpersonal Theme
According to the thematic content and its function, Theme is divided into 3 kinds: topical theme, textual theme, and interpersonal theme corresponding to the three-metafunctional structures of the clause in Halliday's model.
Topical theme can be identified when the first constituent of the clause has a transitivity function such as Actor, Behaver, Senser or Circumstance presented by nominal, prepositional or adverbial groups.Every clause must contain one and only one topical theme.
Textual theme is the constituent which relates the clause to its context, consisting of Continuative Adjuncts which are used in spoken language such as oh, well…; Conjunctive Adjuncts which are used to link clauses together such as or, but, and, nor, yet, so,  'yet' 'as to that' meanwhile, before that, later on, next, soon, finally likewise, in the same way therefore, for this reason, as a result, with this in mind in that case, under the circumstances, otherwise nevertheless, despite that in this respect, as far as that's concerned Interpersonal theme can be recognized when the first element of the clause to which a Mood label can be assigned, signifying the type of interaction between writers and readers, including Finite (do, does, can…); Mood Adjuncts (probably, maybe…); and Vocative Adjuncts (personal names or other forms of direct addresses), Polarity Adjuncts (yes, no), and Comment Adjuncts (fortunately, surprisingly..).

Simple and Multiple Theme
Based on its internal structure, Theme is divided into two subtypes: simple and multiple theme.
A simple theme is made when only a topical element occupies the thematic position.A multiple theme is the theme that consists of the topical theme together with the appearance of other elements such as interpersonal and/or textual themes before it.

Methodology
Drawing on Systemic Functional Linguistics developed by Halliday and Matthiessen (2014) as an analytical tool, the study explores how themes are deployed in IELTS essays.In this study, the data were writing essays collected from two domains: 30 IELTS essays written by English-majored students as texts (Data 1), and 30 sample essays scored from 7.0 to 7.5 (Data 2).
The study employed descriptive approach to conduct an in-depth analysis of theme types in 7.0 -7.5 scored essays and those written by English majored students in order to disclose the prominent features in terms of theme selection in the IELTS essays.After the students' papers conducted in the final writing test and the 7.0 -7.5 scored sample essays were collected, segmented into clauses, the types of themes in academic IELTS writing task 2 were examined.The study based on Halliday and Matthiessen (2014)'s model for the analysis of themes which covered the examination in marked or unmarked themes; topical, interpersonal or textual themes, and simple or multiple themes.Then the occurrence frequency of types of themes in each category was counted and listed to be for the analysis.In addition, a comparative method was used to identify the similarities and differences between essays at different proficiency levels in terms of theme selection.Basing on the distribution rates and the differences between the English-majored students' IELTS essays and 7.0 -7.5 scored sample essays, some possible solutions to improving IELTS academic writing were proposed.

Marked and Unmarked Theme
Halliday and Matthiessen (2014) postulated that a clause consists of two components: Theme and Rheme, together forming a message.Theme, the point of departure gives the setting for the rest of the clause-Rheme.The findings show high frequency of unmarked topical themes is found in both the English majored students' essays and 7.0 -7.5 scored sample essays.In particular, the employment of unmarked themes are about as four times as much as the use of marked themes.More significantly, unmarked themes represent about 83 per cent in Data 1, which is slightly higher than unmarked used in Data 2.
The greater employment of the unmarked themes in Data 1 suggests that English majored students have inclination toward unmarked themes to ensure that their clauses are grammatically correct, which is indicative of structural simplicity in their essays.This finding supports Thompson (2014)'s idea that developing writers with limited resources may be restricted to less marked option.2), (3), and (4), the participants people, students, smart phones, states occupy the thematic position serving as grammatical subjects of declarative clauses.They tell what the clauses are about and give the clarity to the point of departure of the message.
It is interesting to find that the percentage of marked topical themes employed in Data 2 is slightly higher than that in Data 1.However, it is notable that marked topical themes in the study only occupy roughly one-fifth of the total topical themes with 255 instances, which is much lower in comparison with those found by Jalilifar (2010).He found 25.5% (27% and 24% in ELT journal and Roshd journal, respectively) of the marked themes used in the Applied Linguistics articles.This could be discussed based on the fact that Applied Linguistics textbooks are written by expert writers, who employed more marked themes to produce more argumentative texts.
When marked themes are employed, it can be indicated that the writers' intention in using these themes may be to direct the readers' focus towards a specific group or phrase or to reveal their personal emotion or stance.Below are some examples of marked topical themes in the study.
(5) ||| Nowadays, the mobile phone and smartphone has played an important role in daily life.||| (Data 1) (6) ||| Throughout the human history, education has been considered as one of the key components of success in life.||| (Data 2) (7) ||| With the advancement of technology, people have access to the mobile and smart phone very easily.||| (Data 1) (8) ||| In a free market economy, wages are proportionate to the value of a particular employee, worker or a hired person.||| (Data 2) The most common forms of marked themes are adverbial groups or prepositional phrases serving as circumstantial adjuncts in the initial position.In Examples ( 5) and ( 6), temporal circumstances, namely nowadays and throughout the human history are used as marked themes, which set up a temporal context for the interpretation of rheme 5 and rheme 6, that is, the mobile phone and smartphone has played an important role in daily life, and education has been considered as one of the key components of success in life.In Example ( 7), with the advancement of technology is used as marked theme, which set up a contextual frame for the interpretation of rheme 7, that is, people have access to the mobile and smart phone very easily.In Extract ( 8), the prepositional phrase in a free market economy setting up a circumstance of location functions as the starting point for the whole clause.
According to Eggins (2004, p. 320), proficient writers opt for marked themes to enhance coherence and to highlight important ideas in their writing.In addition, Wang (2007) stated that the employment of more marked themes shows the writer's ability to produce more dynamic text, which is a feature of academic writing.Consequently, it is recommended that English majored students should use less unmarked and more marked to foreground important points, to create a more argumentative writing, and avoid repetitious employment of themes in the subject position in the text (Butt et al., 2000), thereby, producing an effective flow of information in the argument.The analysis indicates that topical themes, which have a transitivity function are the most common themes in the data with 1,391 times, occupying about 60,9%.The high percentage of topical themes in writing may show that the students effectively orient the readers to what their writing texts are about (Eggins, 2004).Textual themes are the second most frequently employed type in the essays with 795 cases, equal to 34.8%.Textual themes are used to signal how the clause as a whole fits cohesively with the preceding clauses in the text.Consider the following extracts from the essays.9), (10), and ( 11), the writers use secondly in the theme position to show temporal relationship, for example to give more additional information to the previous clause, and so to indicate causal relationship.In Extracts ( 12), (13), and ( 14), the conjunctive adjuncts namely on the other hand, furthermore, in conclusion, function as textual themes to indicate adversative relationships, give additive information to the previous clause, or to construe summation.These resources enable the writers to manipulate the flow of information, to provide a cohesive tie to the previous clauses, forming a logical relationship in their essays.Eggins (2004) defined textual components as those that contribute significantly to the cohesion of the text although they do not reflect any interpersonal or experiential meaning.Hence, it is recommended that IELTS test-takers should appropriately employ textual themes which involve the use of conjunctions, that is, words or groups that either indicate paratactic or hypotactic relationships.The most common conjunctions in writing are conjunctive adjuncts, namely that is, in other words, for instance…, showing appositive relationship; briefly, to sum up, in conclusion…, representing summative relationship; in addition, moreover, besides.., revealing additive relations; however, nevertheless, on the other hand.., indicating adversative relation; meanwhile, finally…, showing temporal relations; in the same way, likewise.., indicating comparative relation; therefore, as a result, for this reason, illustrating causal relationship.

Topical, Interpersonal and Textual Theme
The percentage use of interpersonal themes is about 4.3%, the least common type of themes found in the essays.The writers tend to utilize few interpersonal themes in order to give their texts an objective style, which is in line with the nature of academic writing.In particular, the candidates in Data 2 applied interpersonal themes at a higher frequency in their writing with 67 instances, compared to those employed by the English-majored students with 30 cases.15), the writers use finite Do (in interrogative structure) as an interpersonal theme before the topical theme, modal adjuncts such as in my view, in general, in my opinion, personally, sometimes in Extracts ( 16), ( 17), ( 18), ( 19), and (20) to draw the readers' attention or to express their own angle on the argument in their writing.The employment of interpersonal themes in the writing is to foreground their position or point of view, or to express their attitudes towards the issue in the text (Droga & Humprey, 2003;Emilia, 2014).
Although the findings indicate that the writers of IELTS essays display greater tendency towards employing the textual themes compared to the interpersonal themes, creating cohesive essays with an impersonal tone, it is recommended that a few interpersonal themes should be subtly employed in order to show the writers' point of view, build up and maintain appropriate relationships with examiners.

Simple and Multiple Theme
Table 3 As can be seen from Table 3, multiple themes (58.7%) are more frequently employed with 834 instances, making up 58.7% than simple themes with 586 cases, equal to 41.3%.In particular, multiple themes are applied at a much higher frequency in Data 2 than in Data 1, at 60.8% and 57% respectively.The discrepancy in multiple theme deployment can be traceable to IELTS writers' level of language proficiency.Multiple themes may consist of interpersonal, textual, and topical components, but the topical element is always required.It is obvious that the beginning of clauses with simple themes is insufficiently academic for IELTS writing.Therefore, it is recommended that IELTS writers should make good use of multiple themes in their writing in order to demonstrate high level of English proficiency.22), the textual theme secondly marking the enhancing relation is placed before the unmarked topic theme computers.
In Extract (23), the conjunctive adjunct in addition acts as a textual theme to introduce an extension of information to the previous clause, preceding the topical theme smart phone and tablets, which together forms a multiple theme.In Examples ( 24) and ( 25), the textual themes in conclusion, construing summation; and, introducing an additive point; but, indicating a contrastive idea, the interpersonal theme in my view, expressing the writer's point of view, are placed before the topical themes, artists, government support, its disadvantages, the technology, respectively to constitute multiple themes.
It is worth noting that multiple themes in Excerpts ( 26) and ( 27) consist of three elements, textual themes (on the other hand, however), interpersonal theme (in my view) and topical themes (schools, this technology) with the ordering of components, that is, Textual ^ Interpersonal ^ Topical.

Conclusion
The present study investigates types of themes deployed in academic IELTS writing, applying Halliday and Matthiessen (2014)'s functional model of Theme-Rheme in English in order to figure out their distribution rates and identify their similarities as well as differences in English-majored students' IELTS writing task 2 and academic IELTS sample essays with band scores of 7.0 -7.5.
The findings reveal that both the English-majored students' essays and 7.0 -7.5 scored sample essays frequently use unmarked topical themes.However, 7.0 -7.5 scored sample essays employ a greater proportion of marked topical themes compared to the English-majored students' essays.Therefore, it is suggested that English-majored students should utilize more marked themes to prevent repetitive use of themes in the subject position, to draw readers' attention to specific information or to create emphasis within their writing, thereby enhancing the argumentative nature of their writing.In addition, IELTS writers are advised to effectively incorporate multiple themes in their writing in order to demonstrate a high level of English proficiency.
Regarding topical, interpersonal and textual themes, topical themes are the dominant types of themes used in the essays.However, the writers display a higher tendency towards using the textual themes to guide the readers from one idea to the next smoothly, creating a more cohesive flow of information in the essays, contributing to overall fluency in writing.Despite its lower usage in academic IELTS writing, a few interpersonal themes should be subtly deployed in order to expresses the writers' attitude, establish and maintain appropriate relationships with examiners.
It is hoped that this study will enable IELTS test-takers in general and English-majored students at Quang Nam university in particular to take into account theme choice and, in doing so, produce academic IELTS essays more effectively, gaining a higher score in their IELTS writing test.

Table 1 .
The distribution of marked and unmarked theme

Table 2 .
The distribution of topical, interpersonal and textual theme The following examples illustrate the use of interpersonal themes in the essays.

, in my view, this technology has
Below are some examples of multiple themes used by the writers.more advantages than disadvantages.||| (Data 1) The multiple theme in Example (21) includes the textual theme on the other hand, signaling an adversative relationship between what has been mentioned before and what is going to be stated, and the marked topical theme apart from numerous advantages while in Example ( (21)||| On the other hand, apart from numerous advantages, the phones have