Investigating Metadiscourse Markers in Book Reviews and Blurbs: A Study of Interested and Disinterested Genres

Informed by the need to study metadiscourse, the present study aimed to compare book reviews ‎and blurbs as examples of disinterested and interested genres in four disciplines of applied linguistics, literature, history, and psychology‎. The study relied on two corpora: (a) 200 book reviews in each discipline between 2005 and 2015 (b) 4282 blurbs in the above disciplines within the same time span. To analyze the texts, Hyland’s (2005a) classification of metadiscourse markers was employed. The findings of the study showed that the frequency and type of metadiscourse ‎markers in blurbs and book reviews are genre dependent. Generally, ‎metadiscourse markers preponderated in the book reviews than in the blurbs (44.5 ‎vs. 32.8 per 1000 words), which can be ascribed to the functionally dissimilar communicative ‎purposes of the two genres. ‎The insights gained from this study can be of tremendous help to ‎deepen our understanding of these genres and to show how evaluation and other textual ‎features of writing are verbalized across disciplines and across genres. ‎ DOI: http://dx.doi.org/10.5755/j01.sal.33.0.19415


Introduction
Academic genres cover an enormous range, and represent what Bhatia (2004) calls a "genre colony". One of these academic genres is undeniably the review genre in which evaluation of the scholarly product is an indispensable part. Scholarly reviews have drawn the attention of researchers across a wide array of academic fields ). Among these review genres, book reviews (BR) and blurbs appear to be functionally different. They comprise genres with the same content but with different objectives and different levels of interestedness (Shaw, 2009). By interestedness is meant the extent to which the author of the text attempts to advance the book by applauding its positive features or presenting an unbiased, objective, and balanced evaluation of the content of the book (ibid). It is therefore possible to arrange genres on a cline of interestedness toward one end of which a genre might be more positively addressed (i.e., interested) and toward the other end, a genre could be more objectively evaluated (i.e., disinterested). Although both of these genres are considered as a reflection on an intended book, book reviews seem to play a greater academic role than blurbs. In fact, blurbs take their identity from two distinct domains (i.e., academic literacy and commerce) (Jalilifar & Banari, 2011).
As a disinterested evaluative genre, the purpose of book reviews is to present a forthright evaluation of a book focusing on positive and negative points simultaneously (Shaw, 2009). According to Lindholm-Romantschuk (1998), book reviews are scholarly evaluations of works done in a specific community. Academic book reviews are a special type of academic writing that, besides helping motivated readers to keep abreast of the latest publications in different disciplines, describe and evaluate these publications (Burgess & Fagan, 2004; Gea- Valor, 2000; Motta-Roth, 1998; Suarez & Moreno, 2008).
As an interested genre, on the other hand, a blurb is aimed at promoting the book sales by celebrating its content positively (Shaw, 2009). The term blurb has been defined in many ways but, simply, it is the linguistic content presented on the back cover of hard copies of books or electronically on the Internet (Basturkmen, 2009). As an example of "the colony of promotional genres" (Bhatia, 2004, p.60), the function of blurbs is not only to describe the content of a book, but also to evaluate and recommend it by praising the positive qualities of the book and the author (Valor, 2005). They perform these functions by means of a restricted set of lexical, pragmatic, and textual devices (Cacchiani, 2007). Therefore, it goes without saying that evaluation constitutes the main function of these two genres but with significantly different effects. Clearly, in both genres, there exists a shared element of persuasion. However, this shared element of persuasion seems to work in different ways to make two entirely distinct genres. In other words, despite using broadly similar structures, fundamentally different evaluative functions can be observed in book reviews and blurbs. This is achieved by relying either on the clause relations to perform the evaluation or on different grammatical structures and constructions to evaluate a book. According to Shaw (2009), the most useful way to carry out the evaluation and maintain an interpersonal relationship with the reader is to apply overt vocabulary items.
The past decade has witnessed a dramatic increase in published research on blurbs and book reviews. In relation to book reviews, for instance, researchers have investigated evaluative speech acts across disciplines (Hyland, 2000), pragmatic purposes of metadiscourse markers (Tse & Hyland, 2006 a), phraseology and epistemology (Groom, 2009), the distribution of positive and negative critical comments (Moreno & Suárez, 2009), lexicogrmmatical realizations of explicit evaluation (Shaw, 2009), the schematic structure and politeness maxims (Jalilifar & Ahmadi, 2011), and hedging (Itakura, 2013). Research has also witnessed an increasing interest in studying the rhetorical organization of blurbs (e.g., Valor, 2005), their communicative purposes, grammatical structures, and the choice of vocabulary (Bhatia, 2004), the structural components, the generic structure potential and the internal organization of the blurbs (Gesuato, 2007), discursive patterns, linguistic and non-linguistic strategies and disciplinary preferences in blurbs across cultures (Jalilifar & Banari, 2011).
Although the above studies have heightened our awareness of these two genres, they have focused on either of the two in a number of disciplines separately. However, exhaustive studies comparing metadiscursive features in book reviews and blurbs of the same disciplines -as examples of disinterested and interested genres -are sparse in the literature. It is by no means clear why utilizing similar metalanguage results in apparently dissimilar genres, and thus it should be worthwhile to juxtapose samples of these two genres in order to identify their characteristics. Notwithstanding their "interesting generic overlaps" (Bhatia, 2004, p. 55), the specific realizations of their features are inextricably bound up with the social and disciplinary contexts in which they are developed. Given this background, and despite a host of studies on metadiscourse markers in academic contexts, the present study gains credence by pursuing a qualitative and quantitative exploration of metadiscourse use in book reviews (BR) and blurbs (BL)in four different disciplines of humanities (i.e., applied linguistics (APP), English literature (LIT), history (HIS), and psychology (PSYCH)) to address the lacuna in the literature. More specifically, in extending previous research studies, the present study intends to answer the following questions: 1. What types of metadiscourse markers are used across blurbs and book reviews in the above disciplines?
2. What functions are served by metadiscourse elements in an interested or a disinterested genre?
It should be noted that book reviews and blurbs were codified according to their disciplines and genres (e.g., Applied Linguistics Book Review 1: AP BR 1, Literature Blurb 10: LIT BL 10) for referencing purposes.

Theoretical Framework
Metadiscourse, as a rather recent approach, has been extensively utilized both in discourse analysis and language education studies to develop a framework for a more thorough understanding of interactions between writers, readers, and texts (Hyland, 2005a). There are competing frameworks for the description of metadiscourse markers that might have equal reputation in academic or non-academic contexts (e.g., Crismore, 1983;Hyland, 1998a;Hyland & Tse, 2004;Hyland, 2005a;Nash, 1992;Vande Kopple, 1985;Williams, 1981). Most researchers have utilized Vande Kopple's typology (1985) as the base for their taxonomies (e.g., Crismore, 1983;Hyland, 1998a;Hyland & Tse, 2004;Nash, 1992) and made some modifications to that. Generally speaking, these frameworks comprise two main categories (e.g., informational vs. attitudinal; textual vs. interpersonal; tactical vs. lexical) and a number of subcategories of metadiscourse markers. Among these typologies, only the one suggested by Williams (1981) divides the metadiscourse markers into three main categories and six subcategories (hedges and emphatics, sequencers and topicalisers, and attributers and narrators). It seems that the distinctions between these typologies are, to a great extent, related to terminology as there is a considerable overlap between them. Nonetheless, in some cases there are differences in perspective. The framework used in the present study was Hyland's (2005a) classification scheme, which takes a functional approach to texts and seems appropriate for the analysis of blurbs and book reviews. This framework makes a distinction between interactive and interactional resources to represent the organizational and evaluative features of interaction. The interactive dimension includes: _ Transitions (e.g., conjunctions and adverbial phrases including addition, and consequence), e.g., (1) The section on feedback is quite cursory, however, and could have been better developed to make this section stronger. (APP BR) _ Frame markers (e.g., sequencing, label stages, announcing goals, and topic shift markers), e.g., (2) Finally, the book proposes specific research topics, and detailed advice on how to construct tests of language for academic purposes and suggestions for further research. (APP BL) _ Endophoric markers (e.g., markers referring to other parts of the text), _ Code glosses (e.g., reformulations and exemplifications), e.g., (3) As discussed by the authors of the book, a class of statistical models known as the diagnostic classification models (DCMs) can be used for this purpose. (PSYCH BR) _ and Evidentials (e.g., expressions referring to other texts in the literature), e.g., (4) As Connor-Linton (1995) pointedly urged, we have to look 'behind the curtain', into 'raters' minds', to examine what composition assessments really involve. (APP BR).

The interactional dimension includes:
_ Hedges (markers signalling the authors' unwillingness to commit themselves to the truth value of the propositions), e.g., (5) While those with a keen interest in the events in question will appreciate the narrative's preciseness, casual readers and even Vietnam War scholars are likely to feel overwhelmed by it. There is so much information in this book that it is difficult at times to follow the main storyline. (HIS BR).
_ Boosters (e.g., markers indicating authors' certainty about the propositions), e.g., (6) And since Hasko finds it difficult to maintain the distinction between the strong and the weak versions of the LRP even for proficient L2 speakers -'devising new ways to describe motion is not a trifling undertaking' (p. 57) -there is a sense in which she (like the other contributors) is fixated on surface structures which, of course, differ (reader-oriented). But the trick -and the task -of learning a foreign language is to go beneath the surface. (APP BR) _ Attitude markers (e.g., markers signalling an author's emotional attitude towards the propositions), e.g., (7) Together, the volume is the most comprehensive and expansive critical handbook of Indigenous American literatures published to date. (LIT BL).
_ Self-mentions (e.g., markers referring directly to the author of the text), e.g., (8) I think it would have been useful to provide more extensive information on British usages that are restricted in some way and to distinguish between usages that are standard British and those that are not. (APP BR) _ and Engagement markers (e.g., markers making explicit interactions with the reader), e.g., (9) As we know now, not only the feature films were fictitious, but also many of the documentaries were also staged. Cameramen created many of the iconic images of the war. Soviet documentary makers made the soldiers repeat the great moment in November 1942 when the two army groups completed the encirclement of the German 6th army. (HIS BR)

Methodology The Corpus
The sample consists of e-book reviews and e-blurbs systematically selected between 2005 and 2015. The reviews were divided into four separate sub corpora: applied linguistics, history, psychology, and literature. To select the book reviews, we relied on two sources of information: (a) a list of English-medium ISI journals from the Social Sciences Citation Index (ISI Web of Science, 2015) and (b) five experienced researchers in each discipline to nominate five prestigious journals. All the journals were reputable, academic and peer-reviewed in the respective fields. The downloading process started from the last issue of the intended journals downwards to reach about 200 book reviews in each discipline amounting to more than one million words to represent the four disciplines (see Appendix for the selected journals in each discipline).
The comparative study took account of blurbs as samples of an interested genre, and these were accessed from the online site, Amazon, which introduces new books. To have a more representative sample, we only chose the blurbs of textbooks with diverse topics in the four disciplines of the study. The blurbs were selected within the same time span stated above. The most recent books were selected in each discipline starting from 2015 backwards. This led to collecting 4,282 blurbs which ran over 800,000 words.
The analysis itself was restricted to the body section of book reviews and blurbs, that is, reviewer information, references, titles, as well as authors' names were removed from the analysis. Tables 1 and 2 below summarize the preliminary information about the genres and disciplines in focus.

Table 1
Preliminary information about book reviews

Procedure
With large collections of data in the present study, the ideal would be to analyse all the texts manually to locate every instance of a particular feature. However, manual analysis was not viable in this study, considering the size of the data (over 1,800,000 words) and Table 3 Kappa coefficient for inter/intra coder reliability time constraints. Thus, we opted for a modified corpus-based approach. In this approach, initially, a list of metadiscourse markers searchable with Wordsmith Tools was drawn up.
To compile this list, in the pilot study, first, 20 book reviews and 125 blurbs were analysed manually to see how the framework worked with our data and to recognize different types of metadiscourse markers. To improve the reliability of our text analysis, two independent and experienced researchers were asked to check our initial analysis and the list. Then, Kappa coefficient was administered for each category of metdiscourse markers to estimate the reliability of the analysis. The results are depicted in Table 3  Next, cases of disagreement were resolved or omitted from the data. For example, in example 10, the modal verb must has been used to show obligation; therefore, it does not function as a booster. According to Hyland's model of metadiscourse, must functions as a booster only if it demonstrates possibility.
(10) Objectivity is a central tenet of the scientific process. That is, in order for science to be a successful tool for understanding the nature of reality it must be free from bias. This idea is so core to science that cases of explicit bias (e.g., data fabrication and false reporting of results) are both mystifying and sensational. (PSYCH BR) When the list was compiled, the whole corpus was analysed electronically using WordSmith 6.0 (Scott, 2004 (11) Talk That Counts is a sociolinguistic study of variation in discourse employing quantitative methods to explore age, gender, and social class differences in the use of features such as you know, I mean, adverbs, and pronouns. (APP BL)

General overview
To address the first research question, the raw and mean frequencies of different types of metadiscourse markers were computed across book reviews and blurbs within the four disciplines. Following Tse and Hyland (2006a) and Alkaff (2000), mean frequencies in this study were computed per 1000 words in order to normalize the data. Tables 4 and 5 present the results by the genre and by the disciplines for all types of metadiscourse markers. In the book reviews, there were about 58 tokens or an average of one marker every 23 words in each text. Similarly, there was, on average, one marker every 30 words and about 6 devices per blurb. Being shorter, blurbs might only sporadically exploit devices like frame markers and endophoric markers to show text sequencing . Before moving on to examine the differences between the disciplines, we take a general look at the two genres without taking account of the disciplinary differences. As revealed in the tables above, the quantitative analyses indicate that book reviews comprise significantly more metadiscourse than do blurbs (book reviews, n=43.3, versus blurb, n=32.8 per 1,000 words). Furthermore, the proportion of interactive and interactional metadiscourse markers was dissimilar in the two genres. Overall, congruent with previous studies (e.g., Lee  in which reviewers used considerably more interactional features that accounted for over twothirds of metadiscourse use in their corpora. The reason for the discrepancy between the results of their study and those of the current study can be two-fold: first, in this study, we focused on four similar disciplines of humanities which might in turn lead to the unanimity of the overall metadiscourse use in the two genres. Second, given the time length between these two studies, one decade, the difference might be attributed to diachronic changes in the rhetorical conventions of the genre. More studies on different disciplines are needed to draw a perspicuous picture of metadiscourse use in reviews. In contrast to the reviews, the number of interactional features in the blurbs outran that of interactive markers, meaning that blurb writers seek more to engage with their readers and to foster an interpersonal atmosphere in the text (Hyland, 2005a). More detailed explanation of each interactive and interactional marker, ranked in an ascending order of frequency, will follow.  & Hyland, 2006a & b) in which endophoric markers were absent or very infrequent, there were no cases of this marker in the two corpora, alluding to the particular characteristics of the two genres which, unlike research articles and theses for instance, do not comprise a number of subsections to be referred to. In a similar vein, although considered as "the hallmark of academic discourse" (Lee & Subtirelu, 2015, p. 59), evidentials were not numerous in the two corpora. Evidentials accounted for the fourth subcategory of interactive markers with a relatively considerable difference in percentage points. Obviously, the reviewers tended to include more intertextual material to convince the target audience than did the blurb writers. Note the following examples. In addition to frame markers, the frequency of code glosses was also roughly similar in both corpora (15.94% vs. 14.4%) constituting nearly one third of all interactive markers, making them the second most commonly used subcategory of interactive metadiscourse in both datasets.
(16) Within each of these chapters, there is extensive detail on implementing certain experimental procedures, including analogues of one-way ANOVA, 2 × 2 factorial designs, and phase (also known as AB and ABA) designs. (PSYCH BR 133) (17) It is a branch of linguistics that looks less at the shape or sound of words--morphology or phonology--and more at how our words and sentences are influenced by the society around us--for instance, how the accent or the dialect we use has been shaped by where we come from or which social class we belong to. (APP BL) On the other hand, transitions were the most frequently-used devices accounting for more than half of the interactive markers in the two groups. However, like other studies (e.g., Tse & Hyland 2006 a & b), reviewers made greater use of transitions than blurb writers (29.9% vs. 21.26%).
(18) In a sense, therefore, it is concerned with the familiar outline of the story of the making and unmaking of an African "nation" and its constituent race, ethnic, class, and cultural fragments from colonialism to the present. (HIS BL) (19) The section on feedback is quite cursory, however, and could have been better developed to make this section stronger. (APP BR) Since we found the main differences between these two genres in the subcategories of interactional markers, to address the second research question, the results of the quantitative and qualitative analyses of these markers are presented in the following section.

Interactional Markers
In addition to mitigating the content or illocutionary force of the propositions, writers and speakers use boosters to express their intentions with confidence and strong conviction (Holmes, 1982). In this study, consistent with some previous studies (Hyland, 1998b(Hyland, , 2005a(Hyland, , 2005bTse & Hyland 2006a & b), boosters were one of the least utilized interactional markers in the two genres. Indeed, this marker took the lowest and the fourth rank among interactional markers in the book reviews and blurbs respectively. However, despite being the least frequent marker (1.39% vs. 0.3%), the frequency of boosters was slightly higher in the book reviews than that of the blurbs. By employing boosters, writers indicate that they feel confident to make total commitment to their statements and somewhat limit the way their readers perceive their propositions and approve of them as shown in the following underlined example: (20) Marking departure from studies on history and literature in colonial India, The Oppressive Present explores the emergence of social consciousness as a result of and in response to the colonial mediation in the late nineteenth century. In focusing on contemporary literature in Hindi, Bengali, Gujarati, and Marathi, it charts an epochal change in the gradual loss of the old pre-colonial self and the configuration of a new, colonized self. It reveals that the oppressive present' of generations of subjugated Indians remains so for their freed descendants: the consciousness of those colonized generations continues to characterize the 'modern educated Indian'. The book proposes ambivalence rather than binary categories -such as communalism and nationalism, communalism and secularism, modernity and tradition -as key to understanding the making of this consciousness. This cross-disciplinary volume will prove essential to scholars and students of modern and contemporary Indian history and society, comparative literature and post-colonial studies. (HIS BL 379) The reason for the infrequent use of boosters in blurbs might be that the writers do not want to, at least overtly, impose their personal opinions on the readers and threaten their negative face, thereby giving them the freedom of action. In fact, the incorrect use of boosters by writers might result in their sounding "abrupt, rude, or didactic in different situations" (Holmes, 1982, p. 24).
In line with Hyland and Tse (2004), self-mentions were one of the least frequently applied interactional markers in the two corpora (example 21). That is, it was the least represented interactional marker in the blurbs and took the fourth rank in the book reviews. By adopting a less personal stance, using fewer personal pronouns, blurb writers are more prone to convey a vividly objective impression in their texts and instead focus on the positive characteristics of the intended book. Items like the author and the writer were not functioning as self-mentions in the book reviews and blurbs since they referred to the author of the intended book not the reviewer or blurb writer (example 22). As revealed in Tables 4 and 5, hedges stand in the third place among interactional markers in the two corpora. Reviewers, more than blurb writers, utilized hedges to tone down or mitigate the harshness of their critical evaluations and maintain their interpersonal relationships. In blurbs, on the other hand, the principal purpose is advertising a book and emphasizing its positive aspects. Thus, hedges which might increase reservations, act as hindering strategies to the text popularization (see examples 23 and 24).
(23) In many places, fundamental concepts in measurement are ambiguously defined. More generally, the book could have used a more careful edit. There are a fair number of typographical errors; the latter largely due to formula symbols that failed to reproduce and instead display as blank spaces. (PSYCH BR) (24) With almost 50 chapters written by experts in the field, the range and depth of coverage is unequalled. The contributors are eminent in a wide range of fields, including psychology, linguistics, human memory, cognitive neuroscience, bilingualism, genetics, development and neuropsychology. (APP BL) Accounting for the second most represented interactional marker in the two corpora, engagement markers demonstrated a slightly higher frequency in the blurbs than the book reviews (13.16 vs. 11.98%). Giannoni (2009) explains this difference by putting review genres on the pragma-rhetorical dimension of authorship which he depicts as a continuum of maximum proximity to maximum distance. He regards blurbs as the genre with the highest level of proximity and book reviews with the highest level of distance (see examples 25 and 26).
(25) As we know now, not only the feature films were fictitious, but also many of the documentaries were also staged. Cameramen created many of the iconic images of the war. Soviet documentary makers made the soldiers repeat the great moment in November 1942 when the two army groups completed the encirclement of the German 6th army. (HIS BR) (26) How did whole barbarian peoples migrate across Europe? What were their relations with the Romans? And why did they convert to Christianity? Drawing on the latest scholarly research, this book rejects easy generalizations to provide a clear, nuanced and comprehensive account of the barbarians and the tumultuous period they lived through. (HIS BL) Being quantitatively different in blurbs and book reviews, attitude markers constituted the most frequently used interactional devices in both datasets contrary to the results of some previous studies (Hyland & Tse, 2004;Tse & Hyland 2006a & b). Since we found the main distinction between the two genres in the frequency of attitude markers, we carried out a more in-depth qualitative analysis of this type of marker. The analysis aimed to unveil how attitude markers are ultimately differently treated in blurbs and reviews. It was revealed that the blurb writers employed a more colourful collection of attitude markers than did the reviewers and that these markers mainly consisted of adjectives and adverbs consistent with Shaw's study (2009) in which the most frequent evaluative words were adjectives. As shown in Table 4, blurb writers made considerable use of positive adjectives and adverbs to describe different attributes of the intended book and serve the underlying purpose of the genre. Moreover, semantically, the blurb writers only employed vocabulary items with positive denotation while the reviewers utilized a combination of positive and negative ones. This finding also corresponds to that of Salager-Meyer and Alcaraz Ariza's study (2007) who, in investigating English book reviews, found that 70% of book reviews contained negative evaluations. Note the following example from our data: (27) This book is, however, written by "traditional" experimentalists and lacks substantive discussion of non-experimental and quasi-experimental approaches-including ANCOVA-.like designs and correlation. That sort of discussion is not within the purview of the book, admittedly obvious from the title, but it is a limitation of the text to address only experimental designs. (PSYCH BR 93) The reviewers employ two main strategies to soften their negative attitudes about the books and take the feelings of the authors of the books into consideration. One strategy is that in some cases, using prepositions (e.g., despite) or conjunctions (although, though, while), the reviewers tend to combine positive and negative comments to weaken the effect of their negative evaluations; for example, (28) In spite of these shortcomings, it is a user-friendly textbook that is worth considering in graduate and undergraduate teacher training programs. (APP BR 38) (29) Given the poor state of early modern statistics, the author is compelled to focus primarily on Britain and Germany in the eighteenth and nineteenth centuries. Despite that limitation, he succeeds in integrating many different time-series of uneven lengths and contents into a synthetic picture, and in so doing produces novel results. (HIS BR 73) The second strategy allows reviewers to rely on hedged grammatical structures to express their rather negative opinion about some characteristics of the book without utilizing any overt vocabulary items. In Salager-Meyer and Alcaraz Ariza's study (2007), 12% of English book reviews containing negative attitudes were hedged. They maintain that "… the purpose of hedging in BRs is not only to make the negative appraisals more palatable, but also to help maintain social harmony and solidarity with the reviewee(s)" (p. 161). In this regard, Holmes (1984) introduces mitigation of a negatively affective speech act as a strategy that contributes to the development and improvement of the relationship between the speaker (writer) and hearer (reader) and reduces the social distance between them: Turning now to the blurbs, the generic structure of a blurb is said to comprise three basic moves: (a) description, (b) evaluation, (c) about the author (Valor, 2005). Among these three moves, (a) and (c) are obligatory and (b) is considered optional. In fact, these moves perform quite different functions: the obligatory moves perform an informative function and the optional one fulfils a persuasive function (ibid). However, it seems that in an interested genre like blurb the second move is the most decisive as it incorporates evaluative language to persuade the reader. However, in many cases blurb writers rely on the first move and do not include the other two moves in their texts. In other words, they do not utilize any overt positive vocabulary items about the book or its author and only depict the content or present a brief summary of the book. What remains a major question here is how such a text that is devoid of any attitude markers can function as an example of an interested genre. In these cases, the blurb writers implicitly attempt to promote the book by expressing its distinguishing characteristics and qualities. For example, in 33 and 34, by utilizing the underlined phrases, the writer implicitly capitalizes on the comprehensiveness of the book.
(33) The field of "World Englishes" takes on ever more importance in the modern era. Mario Saraceni's World Englishes: A Critical Analysis looks at the developments in the field from a critical perspective. It examines the historical, linguistic, ideological and pedagogical aspects in the study of the ever-evolving forms, roles and statuses of English around the world. The principal aim is to offer a critical overview of the field in order both to inform readers about the main issues at stake and to challenge established positions and descriptive/analytical paradigms.

Conclusion
Research has endorsed the vital role of metadiscourse in developing a cogent argument or a well-grounded discussion in academic writing (Tse & Hyland, 2006a). The findings of the present study indicated that metadiscourse use in blurbs and book reviews is primarily genre-oriented. Metadiscourse markers in the book reviews outnumbered those in the blurbs (43.3 vs. 32.8 per 1,000 words), which corroborates the disparate communicative purposes of these genres. The genre factor appeared to be influential since different disciplines in the same genre followed the same pattern of metadiscourse use. Put more specifically, while interactional markers outnumbered interactive features in the blurbs irrespective of the discipline, interactive markers were more prevalent in the book reviews. Ostensibly, having an organized text that can be followed easily and that comprises the author's real attitude about the book is the major concern of a book review. In blurbs, however, the principal objective is to improve interaction with the reader and present a positively general overview of the book in order to persuade the reader to buy it. In addition to this difference in metadiscourse use between the two genres, comparing the main subcategories of metadiscourse markers revealed that attitude markers in the form of positive vocabulary items accounted for the majority of all markers in the blurbs while this marker formed only about one sixth of all markers in the book reviews. This difference can be ascribed to what Shaw (2009) calls "the scale of interestedness" (p. 217) on which he locates some pairs of genres like book reviews and blurbs. He maintains that interested genres aim to persuade the reader to do something for the producer's benefit. The readers of these genres expect them not to be impartial and express all the relevant facts (Shaw, 2006). Blurb writers, ignoring the negative characteristics, mainly focus on positive aspects of the intended books to enlarge their sales. Indeed, referring to negative features is wholly missing in some genres like publisher's descriptions and blurbs (Gea- Valor & Inigo Ros, 2009;Giannoni, 2009). Shaw (2006) also asserts that particular types of genres make use of specific types of discourse and in evaluative and interested genres the evaluation made is primarily positive. Therefore, aspirant writers must be well-informed about the rhetorical conventions of different genres and their variations in academic disciplines.
The current findings add to our understanding of these genres and of how evaluation and other textual features of writing are verbalized across disciplines and across genres.
However, the generalizability of the results of this study is subject to certain limitations. One source of limitation which might affect its generalizability is that we only investigated book reviews and blurbs of four different disciplines of humanities. The analysis of metadiscourse use in these disciplines does not illuminate the full range and potential of metadiscourse use in these genres. Therefore, further follow-up studies could also be conducted using a more comprehensive corpus consisting of other disciplines to determine interpersonality in these two genres. It would also be interesting to carry out such analyses on other members of review genre families like book review articles in which there is a great deal of interaction between reviewers and reviewees to indicate discrepancies in using metadiscourse resources. Future research can also concentrate on juxtaposing blurbs with other promotional genres like print ads to demonstrate how metadiscourse shapes these adjacent genres.