Abstrak
ABSTRACT Ambriana Shauda (2314.013). An Analysis of Logical Fallacies in Argumentative Writing at the Fifth Semester of English Education Department in IAIN Bukittinggi. Faculty of Tarbiyah and Teacher Training, Islamic State Institute of Bukittinggi. 2019 In argumentative writing, there is a logical fallacy, that can be defined as error in reasoning or informal fallacy, show invalid arguments or irrelevant points that will damage the strenght of the statement. although it has an important role in determining the quality of an argument, the topic of logical fallacy has not been explored in learning, the possible reason is the fact that there are other aspects that require faster intervention, such as grammar, mechanics or organization which aspects were called formal fallacy. This research was purposed to identify and find out the type of informal logical fallacy used by students’ in writing argument text at the fifth semester of English Education Department in IAIN Bukittinggi. This research was done because the researcher found several problems from the students when they were going to write text arguments. Most of them say that they are difficult to develop ideas in writing. The researcher used descriptive quantitative research for this research. The total population was 111 students, the researchers took 25% from the total population as a sample, so the total sample for this study was 28 students and the researcher used a random sampling in determining the sample. The researcher used documentation as a research instrument. To get the data the researcher asked the results of the students' writing in the form of text arguments and the title of the text of each student that have been rated by the writing subject lecturer. Based on data analysis the results of this study indicate that students produce a number of logical fallacies in their writing, such as word ambiguity, misleading euphemism, appeal to fear, hasty generalization, false cause, and slippery slope. Some of the fallacies were very simple and basic so that can actually be avoided through simple instructions. From the results of writing student arguments as many as 9 students out of a total of 28 students made a fallacy in the type of hasty generalization in inductive fallacy, this was caused because the students draw conclusions without providing evidence from experts and the sample of their conclusions is insufficient Key words : logical fallacies, argumentative writing