Genre analysis of texts has always been significant. The current study aimed at investigating intertextuality considering cultural variations and differences in students' discourse communities. Social studies, philosophy, and biology were chosen as the representatives of social sciences, humanities and sciences. Tehran University, one of the most prominent and oldest universities in Iran, was chosen as the source of the theses. From each discipline, eight theses were chosen randomly and the organization of the introductions was analyzed according to Samraj's revised model of Swales (2008). Next, a comparativeand contrastive analysis was performed between the results obtained from this study and the ones obtained from Samraj's (2008). The results indicated that social studies and biology introductions were quite similar and followed the traditional format of thesis writing whereas philosophy introductions were different as they had a more topic-based structure.
Keywords: genre analysis, intertextuality
1.1 Genre and Genre Analysisin Brief
The word Gerne means a particular type of art, writing, music etc., which has certain features that all examples of this type share (Longman Dictionary of Contemporary English, 2008). The term has a wide usage in rhetoric, media, theory, and even education (especially linguistics) to refer to a special kind of text. According to Connor (1996), genres are not static, homogenous texts but truly dynamic and vibrant. Based on what Bakhtin (1986) proposed, texts have ordered and unified forms (as we can see that stories have structures); they are also "intertextual", which means texts need other sources to rely on. Therefore, intertextuality, which is shaping the meaning of a text by referring to other texts, plays a key role in completing the meaning of a text and resulting the meaning of the context.
The definitions of the concepts of "gerne" in gerne analysis (Swales, 1990) and "culture" in intercultural contrastive rhetoric (Connor, 1996) have evolved since they were first presented.
According to Bhatia (1993, cited in Tench, 2003), genre analysis is the study of situated linguistic behavior in institutionalized academic or professional settings which has four main features:
1) Gerne analysis shows a genuine interest in the use of language to achieve communicative goals. Therefore, it is not an extension of linguistic formalism.
2) Gerne analysis does not represent a static description of language use but gives a dynamic explanation of the way expert users of language manipulate generic conventions to achieve a variety of complex goals. In fact, it combines the advantages of sociolinguistics perspective with those of cognitive perspective.
3) It is primarily motivated by applied linguistics concerns, especially language teaching at different levels.
4) It is narrow in focus but wide in vision, which allows it to focus on specific differentiation in language use at various levels of generality.
According to Bhatia (2002), gerne analysis is a means to understanding the realities of the world of the texts and as he states, the world we experience is both complex and dynamic. Its complexity is due to the existence of various textsof different types and these texts often serve overlapping and conflicting communicative aims. He noted that genre analysis has three prominent frameworks:
1) Corpus Studies - the computational analysis of language
2) Textual Analysis - linguistic descriptions of texts
3) Critical and ethnographic analysis - interviews and case studies
Paltridge (2001) argues that gemes need to be considered not as patterns of texts in isolation but in relation to the context of production and interpretation and to the aims and assumptions of particular discourse communities.
According to Berkenkotter and Huckin (1995, cited in Bhatia 2002), gerne knowledge is a form of situated cognition and it is inseparable from writer's socialand procedural knowledge. …