CHAPTER II THEORETICAL FOUNDATION Chapter two presents several theories that are related to the research. In detail, this chapter explains about writing, teaching writing, collaborative learning and Jigsaw technique as the basis investigating the research. 2.1. Writing Theory 2.1.1. Definition of Writing Writing is functional communication, making learners possible to create imaginative world of their own design (Kern, 2000). Writing is one of four language skills that should be mastered by students. It is considered as the most difficult skill because the writer has to make some aspects in writing such as content, organization, purpose, punctuation, vocabulary, grammar and spelling in a balance way. It requires a great intellectual capacity to produce a good writing product. Langan (2011) said that writing is a skill. It means that writing is a skill which can be learnt by anyone by practising and hard work, because it is not a natural gift. Writing is a discovery process which involves ideas, how to organize them to be coherent and structural. In the other words, writing is the mental work of inventing ideas about how to express them into statement and paragraph. It means that writing is a way to produce language that comes from one’s thought. According to Clouse (2005), writing is a skill of English language which requires students to represent and develop their own idea in a written form. Many students feel confuse on how to begin to write a paragraph or get stuck on