The Use of Wall Charts in Instruction to Improve the Eighth Grade Students’ Vocabulary Mastery (An Experimental Study at SMP Negeri 4 Banda Aceh)

Vocabulary refers to list or a set of words individual speakers of language might used. Hammer (2011) explains that teaching vocabulary does not only teach new meaning of words but also teach how to spell and how to pronounce the words. Teaching vocabulary in the early English learning is very important. Students will find difficulties in learning English if they lack vocabulary. Vocabulary much more than grammar is the key to understand what students hears and reads in school, and to communicate successfully with other people. For this reason it is very important for students to build up a large store of words. Vocabulary is the most important component language because it affects the four language skills that are listening, speaking, reading, and writing. Related to the importance of vocabulary in language learning, Decarrico in Celce and Murcia (2001), states that vocabulary learning is central to language acquisition, whether the language first, second, or foreign. The reason of why vocabulary is important in learning language is implicitly proposed by McCharty (2010), he said that when people speak of the vocabulary of language people ARTICLE HISTORY


INTRODUCTION
Vocabulary refers to list or a set of words individual speakers of language might used. Hammer (2011) explains that teaching vocabulary does not only teach new meaning of words but also teach how to spell and how to pronounce the words. Teaching vocabulary in the early English learning is very important. Students will find difficulties in learning English if they lack vocabulary. Vocabulary much more than grammar is the key to understand what students hears and reads in school, and to communicate successfully with other people. For this reason it is very important for students to build up a large store of words.
Vocabulary is the most important component language because it affects the four language skills that are listening, speaking, reading, and writing. Related to the importance of vocabulary in language learning, Decarrico in Celce and Murcia (2001), states that vocabulary learning is central to language acquisition, whether the language first, second, or foreign. The reason of why vocabulary is important in learning language is implicitly proposed by McCharty (2010), he said that when people speak of the vocabulary of language people are primarily but not exclusively, teaching about the words of that language. Therefore, if vocabulary is related tightly to the learning words of certain language, then it will be central in language learning. For instance, all languages in this world are used by help of words. Words mean onnecting language to the real world. They can be the represent of things in the real life and also used to express feelings of the language user.
Teaching vocabulary for beginners is not easy. Forts (2008) states that teaching vocabulary is quite difficult because there are thousand hundreds words in English. The teacher has to introduce new words and ask the students to practice them, making clear the meanings and the ways in which each can be used. However, many students still get difficulties in increasing their vocabulary mastery. Bowen (2004) states visual aids are great help stimulating the learner of a foreign language. The students must use their ears as well as their eyes but it is the eye that is primary channel of learning. Good visual materials will help maintains the pace of the lesson and the students' motivation.
Some pictures actually are perfect for the purpose of teaching particularly the vocabulary. There are many types of pictures that are proposed by some expert; one of them is wall chart. Wall Chart is large card displaying diagram or picture. Most wall charts consist of combination of visual and verbal material. While Doff (2008) states that a charts (sometimes called wall chart) is a large sheet of paper or card with writing, picture or diagrams which the teacher can either hold up for the class to see or display on the wall or blackboard used for extended presentation or practice. Wall chart is one of suitable media to teach vocabulary for children. Basically, children love the interesting picture. It makes the teacher easier to give explanation about new vocabulary to young learners. Bowen (2004) also states that wall chart suitable for pair or group work in intermediate and advance classes and unsuitable for whole class teaching because it is usually complex, with printing too small to be seen by the student from their seats.
The reason of why wall chart is used as the way to enrich the students" vocabulary is that young learners as the object of the English language learning are usually interested in a real-life activity. It is also stated by Phillips (2006). "Vocabulary is best learned when the meaning of the word(s) is illustrated, for example by a picture, an action, or a real object. The children should then meet and use the word(s) in relevant contexts, in order to "fix" them in their minds. This helps establish their relationship to other words, so that a vocabulary network is built up.
According to Wingenbach (2010), by wall chart the teacher will get more advantages, because teaching vocabulary to children by using wall chart can; (a) quick way for the students to visualize what the teacher are saying --numbers, trends, up or down; (b) forceful --emphasizes main point; (c) convincing --proves a point, see and hear; (d) compact way to convey information; (e) more interesting than just talk or print (Remember to use as many of the five senses as possible).
In presenting vocabulary, Cross (2009) points out a design to explain an enrich students" vocabulary using wall chart with step as follow: (1) Sound and the meaning. In this steps, when the teacher teach the word "kite" it is easier for the students if the teacher pronounce the word to them and show them at the same time the object of the picture, that the students, get the meaning immediately.
(2) Repetition, in this step, the teacher gets the class to repeat the words that they have learn a few times. It is help the students to practice how to pronouncing words correctly and remembering meaning of words.
Thornbury (2005) states that the time-honored way of memorizing" new material is through repeated rehearsal of the material while it is still in working memory. However, simply repeating an item (the basic of rote learning) seems to have little long-term effect unless some attempt is made to organize the material at the same time.
(3) Written Form, the teacher writes the word or sticks the words under picture to show the meaning of the picture. It helps the students to know how to write words of that meaning correctly.

MATERIALS AND METHODS
The study was conducted from March 5th, 2018 to May 8th, 2018. Wall charts analysis were conducted at SMP Negeri 4 Banda Aceh. . The total population is 115 students who are composed of five classes; class VIII1, class VIII2, class VIII3, class VIII4, and class VIII5In this case, every class was taken 6 students for experimental group and 6 students for control group. Thus, every group consisted 30 students. Therefore, the total sample was 60 students. Choosing students for experimental and control group was conducted randomly. There were two kinds of test; pre-test and post-test. Pre-test was given in order to know the condition of the students before treatment and post-test was given to know the effect of the charts. The writer given 60 questioin to the students that are 20 questions for adjective, 20 questions for nouns and 20 questions for verbs. Where are the question divided by two groups that are 30 question for experimental group who are though vocabulary by using wall chart and 30 questions for the control group who arethough vocabulary without using wall charts.

A. Pre-Test
Pre-test is given with the intention to find out if there are students who already know about the material to be invited. Pre-test can also be interpreted as activities that conveyed student's knowledge of the material to be delivered, pre-test activities carried out before the given activities are given. The benefit of holding a pre test is to find out the student's initial ability regarding the lesson being delivered. By knowing the initial abilities of these students, the teacher will be able to determine how the delivery of lessons will be discussed later.

B. Post-test
The post-test procedure is a form of questions that are given after the lesson / material submitted. In other words, a post test is a final evaluation when the material taught on that day has been given in which the teacher gives a post test with the intention of whether students have understood and discussed about the material just given that day. The benefit of holding this post test is to get a picture of the abilities obtained after finally from the delivery of lessons. The results of this post test compare with the results of pre tests that have been done so that it will prove far more effective or the results of what has been done, besides being able to verify which parts of the material are still not studied by most students.

Statistical Data Analysis
There are two kinds of tests, they are pre-test and post-test. Pre-test was given to the students before the teaching learning process, and post-test was given at the last meeting after the teaching learning process. The result of pre-test and post test of experimental group with wall charts by using SPSS 18.0. Based on the statistical summary above, the two mean scores of the pre-test results were calculated for experimental group and control group. Both of them were compared by employing paired sample t-test. As shown in the table above, the mean score of the pre-test of experimental group with peer support is 37.70. Both mean scores were compared through paired sample t-test with the level of significance 0.05.
Based on the comparison of the two means, the result of t-table with the level of significance 0.05 is 0.668 and the result of t-test is lower than t-table (-276 < 0.668). This finding indicates that there is no significance between the result of pre test of the experimental group with wall charts and control group without wall charts. Thus, the conclusion is that the previous students' ability in vocabulary of experimental group with wall charts and control group without wall support is similar. Based on the statistical summary above, the two mean scores of the post-test results were calculated for experimental group and control group. Both of them were compared by employing paired sample t-test. As shown in the table above, the experimental group and control group. Both of them were compared by employing paired sample t-test. As shown in the table above, the mean score of the post-test of the experimental group with wall charts is 69.06. Both of the mean scores were compared through paired sample t-test with the level of significance 0.05.
Based on the comparison of the two means, the result of t-table with the level of significance 0.05 is 0.668, and the result of t-test is higher than t-table (69.06 > 0.668). The finding indicates that there is a difference between the result of the post-test of the experimental group with wall charts and control group without wall charts. Thus, the conclusion is that the vocabulary skill of experimental group with wall charts and without wall charts after the implementation of wall charts is different. The result of t-test is used to prove the hypotheses by It aims to find out whether the null hypothesis or the alternative hypothesis is rejected or accepted. The null hypothesis is that the students' score before and after the treatment are different. The level of significance is 15 % (0,05) the following probability.. After comparing the two means, the result of t-table with the level of significance 0.05 is 0.668 and the result of t-test is lower than t-table (-14.37 < 0.668).
Hence, Ho is rejected and Ha is accepted.This indicates that there are significant differences between the two means of pre-test and post-test of experimental group with wall charts. Based on the calculation above, the t-test is -9.00 with the level of significance 0.05. The t-test result is -9.001<0.668), hence Ho is rejected and Ha is accepted This indicates that there are no significance differences between the two means of pre-test and post-test of experimental group without wall charts. In other words, there is no progress of the students' mastering vocabulary in control group without wall charts.

Discussion
Before conducting experiment, the writer gave pre-test and the result of pre-test showed that the students, average score of experimental group is 37.70. After the writer gave treatment, the students' average score of experimental group is 69.06. In can be said that the students' ability in mastering vocabulary before treatment was 37.70 and it is not satisfying. Meanwhile after treatment, the students' ability in mastering vocabulary increases 69.06. Next, in conducting experimental teaching, at first the writer gave a pre-test to both groups (Experimental and Control Group), the scores obtained by the students showed that there was no significant difference between two groups in which the pre-tests. T-test with level of significanct 0,05. After comparing two means, the result of t-table with the level of significance 0.05 is 0,668 and the result of t-test is lower than t-table (-276 < 0,668). This find indicates that is no sfnificance between the result of pre test of the experimental group and control group.
Then, the writer used wall charts as media in teaching vocabulary to Experimental Group. After teaching and learning process (tretament), there was a significant difference between the two-groups. It was proven by the result of the post-test in which the post-test scores (69.07) were greater than the pre-test scores (37.70). Next, the statistical analysis indicates that the post-test t-test of both groups is 3.028. The critical value of t-test for the degree of freedom 0, 668 at the level of significance 0.05. The result indicates that t-test (3.028) is bigger than t-table (0,668). In other words, the students' scores of experimental group were greater than the students of control group.