【正文】 nto how much time middle school students spend learning English”, we mean that we are doing research into this issue. However, in the sentence “After six years of study in school, he successfully entered Zhejiang University at the age of 17”, the “study” used here is generally not interpreted as “research”.Nowadays, it is reasonably acceptable to say that students can not only study but also research. Researchers need to study in the course of research. To be teachers, they should do some research while continuing their study of what they are teaching in further education. In order to promote English language teaching (ELT) in schools and colleges in China, this paper will first discuss the role of research in the acquisition of knowledge, then examine the kinds of study, and finally explore the dynamic interaction between study and research in terms of educational theory and practice in ELT settings.2. Three sources of knowledge二級及以下各級小標(biāo)題單獨(dú)占一行，左頂格，Times New Roman小四號，正體。）. The role of research in the acquisition of human knowledge can hardly be understood fully without being studied in connection to that of experience and reasoning. For the purpose of achieving a better understanding of research, the role of experience and reasoning will be considered before that of research. ExperienceExperience is a kind of development of personal knowledge of the world. It is regarded as an individually accumulated body of knowledge (Cohen and Manion 1). In a problemsolving situation, people tend to resort to personal experience first. However, where solutions to problems clearly lie beyond this body of personal experience, it is often helpless to resort to personal experience. In the case of foreign language learning, the learner’s native language often interferes with or facilitates the learning of the target language. This can be considered as a clear indication of the learner’s reliance on the personal experience in his or her first language. It is arguable that the personal experience is by no means reliable although it is sometimes helpful because it cannot guarantee smooth progress and success in foreign language learning.As for English language teaching, our experience of English examinations can be resorted to when we help our students prepare for the college entrance examination of English. However, it is difficult for us to resort to our previous personal experience when we are facing the problem of how to motivate middle school students in municative language teaching as many of them can hardly see any chance to municate directly with native speakers of English. ReasoningReasoning is the act of forming conclusions, judgements or inferences by thinking in a logical manner. There are two basic types of reasoning: one is inductive reasoning and the other is deductive reasoning.Inductive reasoning begins with observations and evidence of empirical regularities or empirical relationships (Howard 8). This is a mental process from a number of specific cases to a general idea underlying them. When a learner of English es across expressions such as “three books”, “many ships”, “two minutes”, he or she may form a hypothesis that “s” is used to indicate the idea of “two or more”. It is not difficult to see that inductive reasoning in foreign language learning often leads to hypothesis formation.Deductive reasoning begins with basic beliefs, theories, assumptions, propositions, and so on, the validity of which is assumed and untested (Howard 8)頁：2夾注的格式要求：所引文獻(xiàn)的作者在正文中不出現(xiàn)的情形：根據(jù)MLA格式，“作者的姓”加上“引文出現(xiàn)的頁碼”，不加文獻(xiàn)的出版年份。（見《MLA科研論文寫作規(guī)范》第212213，64頁。 2) the logical development of these hypotheses。） A Comparison between Experience, Reasoning and ResearchExperienceReasoningResearchSystematic and controlled√√Empirical√√Selfcorrecting√When we bine experience and reasoning through research, we can reflect on experience to form hypotheses through reasoning and, at the same time, obtain empirical evidence through experience to test and modify the hypotheses derived from reasoning. For example, when a learner first resorts to inductive reasoning to form the hypothesis that “s” indicates the idea of “two or more”. Later, the learner may happen to produce output such as “*one and a half hour” through deductive reasoning on the basis of the existing hypothesis and get the corrective feedback from the teacher. With such feedback as negative empirical evidence, he or she would modify the existing hypothesis to reach the conclusion that “English makes the division after ‘more than one’” (Quirk et al. 297).3. Four types of studyIn a generally accepted sense, study refers to the mental activities in acquiring knowledge. According to The Random House Dict