THE INFLUENCE OF TEACHING PREFIXES AND SUFFIXES IN CONTEXT ON DEVELOPING STUDENTS’ ENGLISH VOCABULARY AT SMAN 2

Vocabulary through morphemes provides meaningful vocabulary acquisition skill. Students learn to guess the word meaning by looking for prefixes and suffixes in context. The students analyze prefixes and suffixes within the words. Then, the students analyze other context clues such as part of speech around the words. The purpose of this research is to uncover the significant difference between the influence of teaching prefixes and suffixes in context and


INTRODUCTION
Knowledge of words is one of the important parts in conducting oral and written communication. We can express meaning, thought, idea, and opinion, we can understand the meaning of words, and we can understand English textbook and lecturer's explanation if we have knowledge of words. Therefore knowledge of words is needed in oral and written communication.
Vocabulary is one language element that links the four basic language skills: listening, reading, speaking, and writing. To learn the language skills, students need to study vocabulary. We should have rich vocabulary as the main basic to be able to comprehend English text. If we only have limited vocabulary, we will not understand English text effectively.
The researcher did the interview to two English teachers of SMAN 2 Garut. They told much information about the English teaching and learning process of their classes.
The first teacher said that the English students' ability was average. There were some students had a good ability or had a basic of English, but some others were still low yet.
Whereas, the second teacher said that the students' vocabulary mastery was low. They both explained that the students were difficult to distinguish parts of speech, so they were confused to use the correct form of prefixes or suffixes.
Basic English vocabulary needs 10 thousand vocabularies. The number of 10 thousand is standard in the world for those who are learning English. If an English learner has mastered 10 thousand words, then he or she was able to communicate in English.
However, this amount is still felt quite heavy to be mastered. But the curriculum in Indonesia stated that the high school or high school graduates must master the vocabulary is very often used where the amount is 4,000 vocabulary. Therefore vocabulary is very important for foreign students in learning English.
When the students read a paragraph in reading passage, the students usually find out some unknown words. Some unknown words may contain prefixes and suffixes. Nagy and Anderson (1984) as in Susan M. Ebbers (2009:10) estimates that school texts contain 88.500 distinct words, each word has related form which meaning might be inferred through morphemic and contextual analysis.
Memorizing new words list is more popular than analyzing prefixes and suffixes for most foreign learners in learning vocabulary. The English language teachers often forget to explain how word structures are formed. They should explain that sadness is formed by sad (adjective) + the suffixes 'ness' and that the suffixes 'ness' can be used in forming other words such as happiness (noun). Yousef Sharif Tahaineh (2010: 4) says: "Students memorize the syntax of the language (i.e. phrases, clauses and sentences) without providing any kind of activities that help them understand how word structures are formed. This makes the learning process more difficult and burdens the students with the necessity of memorizing still more word forms resulted from the continuing different word-formation processes." Analyzing prefixes and suffixes would be powerful technique if the teacher use context in getting the meaning of the unknown word. Wysocki & Jenkins (1987) as in Susan M. Ebbers (2009:13) says "The use of context to infer the meanings of unknown words is more reliable when readers analyze both the context surrounding the word and the morphemes within the word." Learnng prefixes and suffixes could help students to increase their vocabularies. This is suported by the previous researches. The first previous research is by Fenny Widyawati, Patuan Raja, Deddy Supriyadi about teaching suffixes to increase vocabulary mastery at 2nd grade of SMAN. This research was intended to investigate whether or not teaching suffixes could be used to increase students' vocabulary mastery and which Analysis of the results of independent sample t-test and two-way ANCOVA showed that the experimental group outperformed the control group significantly in the posttest. It was concluded teaching prefixes had a positive effect on learners' vocabulary knowledge.
The fifth previous research is by Intan Pradita Nizamudin Sadiq about developing student vocabulary worksheet by using affixes. This paper aims at describing the stages of developing vocabulary worksheet by using affixes by adopting the process of the same development research of Wutsqo. The results of this study are; 1) the aspect of validity has met the criteria development vocabualry student worksheet to learn the material Yudi Kurniadi additive that has been prepared to have a very good quality, 2) practicality aspect has fulfilled the minimum criteria with certain notes on 21st century learning, 3) The results of the pre-test and post-test student learning augmentation material by using SVW has met the minimum criteria of improvement.
The differences are in the case of the purpose and the subject of the research. The purpose of this research is to uncover the significant difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary development, with the subject of the research is class XI IPA 1 and XI IPS 1 .
Meanwhile the purpose of the first previous research is to know how far is the students' abilities in using prefix and suffix. The second previous research is intended to investigate whether or not teaching suffixes could be used to increase students' vocabulary mastery and which aspect of vocabulary increased the most after being taught through suffixes, with the subject of the research is class XI social 1 of SMAN with the subject of the research is the students of Grammar for English teacher class.
The differences between this first previous and this research is the researcher uses word meaning, word combination, grammar of word to test the students. While in this research, the researcher uses the strategy of word combinaton and context clues to test students' vocabulary. The differences between this second previous , third previous research and this research are the researcher uses verb prefixes ( re-, dis-), adjective prefixes (un-, in-, im-, il, ir-, dis-), noun suffixes (-er, ion/ation, ment), verb suffixes (-en,ify, -ize, -ate), adjective suffixes (-ous, -ful, -able, -less) to test students' vocabulary. In this second previous research, the researcher uses four main parts of speech to test the students' ability in using prefix and suffix. Those were noun, adjective, verb, and adverb.

Meanwhile in this third previous research, the researcher uses prefix inter-, suffixes -ment
and -ion to test students' vocabulary in using prefixes and suffixes. The differences between the fourth and this research is the researcher uses prefixes on vocabulary learning. Meanwhile in this research, the researcher uses prefixes and suffixes in context to develop students' vocabulary. The differences between the fifth and this research is the researcher uses vocabulary worksheet by using affixes. Meanwhile in this research, the researcher uses prefixes and suffixes in context.
According to explanation above, the writer is interested to conduct the research entitled the influence of teaching prefixes and suffixes in context on developing students' English vocabulary at SMAN 2 Garut. Deriving word meaning through prefixes and suffixes is not popular for foreign learners. On the other hand, deriving word meaning through prefixes and suffixes within the words will be powerful strategy if the teachers use context clues around the words such as part of speech, contrast, cause-effect and other clues. Therefore, the writer will investigate students' English vocabulary development by teaching prefixes and suffixes in context and without context. Moreover, the purpose of this research is to compare the difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary development.

Research Method
Based on the objective that would be achieved, the writer uses the experimental method. Experimental method is a method of investigating causal relationships among variables. The writer chooses this method because the writer wants to compare the difference of influence between teaching prefixes and suffixes in context and without context toward students' English vocabulary development.
This research is intended to investigate the two variables: teaching prefixes and suffixes in context and students' English vocabulary development. There are two groups. Group 1, the experimental group receives specific treatment (teaching prefixes and suffixes in context); while group 2, the control group does not receive it (teaching prefixes and suffixes without context).

Yudi Kurniadi
Before conducting the test, the writer conducted try out of the instrument. The try out for the test consists of fifty items and they are in the form of multiple choice.
The result was analyzed for their validity, reliability, and practicality.

b. Pre-test and Post-test Instrument
The writer gave tests to each class both experimental and control group. Their scores were used to determine the differences of the two classes. The pre-test and post-test instrument used the different text but the difficulty level was same. The students' achievement was based on the test. The items were constructed in such a way that they could measure the students' achievement of each group. Most of the test items were adopted from internet and the writer wrote a few items in which the students had to choose one correct answer out of 4 choices. The item for pre-test and post-test consisted of 20 items. This lasted for one period (45 minutes). And the number of the students who sat for the pre and post-test was 66 students.

Research Procedure
In general, the procedures of the research can be described as follows: a. Preparing the materials for teaching and learning process during the treatment.
b. Organizing teaching procedures by arranging lesson plan.
c. Organizing the research instrument.
d. Trying out the research instrument.
e. Analyzing the try out data in order to find out the validity, reliability, and practicality.
f. Conducting the pretest for both groups to find out the initial abilities between the two groups.
g. Giving the treatment to experimental group (teaching prefixes and suffixes in context).
h. Conducting the post-test for both groups to find out the progress of the ability of each group.
i. Analyzing the data.
k. Reporting some conclusions of the result and propose some suggestions that may contribute for the further study. The instrument was tested first in order to find out the validity, reliability, and practicality. It was conducted once another class of the same grade.

a. Validity
Validity is a matter of degree to extend the result of the study as one way to measure the validity by conducting item analysis. In this study, validity test used analisis butir soal.

b. Reliability
To find out the reliability of instrument, the writer used split-half method proposed by Suharsimi Arikunto ( 2009: 93). It splits the odd items and even items. The writer used correlation product moment formula to correlate the two half. Then the writer used Spearman Brown formula to find out the reliability of the whole tests.  Tjokrosujoso (1995Tjokrosujoso ( /1996. Based on the result of the try out test, the test was economical, easy to be administered and easy to give score. It was also full and clear direction.

The Implementation of the Experiment a. Study Agenda
The study was conducted in ten days. The experimental group was given treatment by teaching it prefixes and suffixes in context. The schedule is described by this following table:

b. The Procedures of the Teaching and Learning in Experimental Group
The procedures of the teaching and learning in experimental groups were: b. The writer organized the three lesson plan for first, second, and third meeting.
c. The writer organized the learning material for first, second, and third meeting.
d. The writer taught prefixes and suffixes in context.

Technique for Analyzing the Data
After holding the test, the writer continued computing and analyzing the result of the pre-test and post-test both control group and experimental group through t-test formula. It can be done through the following steps:

a. To formulate Ho and Ha
Ho: There is no significant difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary development.
Ha: There is significant difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary 3) To define the value of Chi-kuadrat counted: If t counted is out of Ho acceptation area, so Ha is received.

Testing Hypothesis
All the process of collecting, analyzing and interpreting the data is aimed at testing the hypothesis. The hypothesis says: "There is significant difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary development.
If analysis of the result of the test shows that tcounted is out of Ho acceptation area, so Ha is received. It means that hypothesis is accepted.

FINDING AND DATA ANALYSIS
This chapter describes the analysis of the data calculation through the result of testing ability scores of the experimental and control group, interpreting the result of computation and the finding. Data computation and the steps of hypothesis testing are also described in this chapter.

Data Calculation
In conducting this research, the writer has collected the data by using pre-test and post-test to both of experimental group and control group. The data have been divided into two groups. Those data are from experimental group and control group. The writer displays data as follows:

Discussion of the Study
Pre-test and post-test result diversities for experimental group and control group are analyzed. It is used to prove the research hypothesis "there is significant difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary development." The scores in experimental group is normally distributed because X 2 counted = 7.18 < X 2 table = 7.82. The scores in control group is normally distributed because X 2 counted = 7.08 < X 2 table = 7.82. The variances for the scores of the two groups are equal because F counted =1.802 = F table = 1.808.M Based on the data analysis, tcounted = 3.5 and ttable= 1.99. Because tcounted value is higher than ttable, so Ho is rejected. As stated on the criteria of hypothesis testing: If -ttable ≤tcounted≤ttable, Ho is accepted Because tcounted= 3.5 is out of Ho acceptation area, between ttable = -1.99 and 1.99, so that Ha is accepted. It means that Ha is accepted, there is significant difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary development in the Second Grade Students of SMAN 2 Garut on ninety five percent (95%) significance level.
The result of research is supported by Wysocki & Jenkins (1987) as in Susan M. Ebbers (2009:13) says "The use of context to infer the meanings of unknown words is more reliable when readers analyze both the context surrounding the word and the morphemes within the word." Then the result of this reseacrh is supported by the first previous result of the research from Fenny Widyawati, Patuan Raja, Deddy Supriyadi about teaching suffixes to increase vocabulary mastery at 2nd grade of SMAN. The result was t-value is higher than t- Criterion Mastery in each cycle is 100%, with the improvement 169.64% in cycle 1 to 180.81% in cycle 2. These indicate that there is a significant improvement of the students' vocabulary mastery through affixation strategy of Class IX-1 of SMP Santo Petrus Medan.
Based on the data analysis, the supporting theory and the other results of the research, the researcher finds out there is significant difference between the influence of teaching prefixes and suffixes in context and without context toward students' English vocabulary development in the Second Grade Students of SMAN 2 Garut on ninety five percent (95%) significance level.

CONCLUSIONS AND SUGGESTIONS
In this chapter, the writer presents the conclusions of the research and suggestions as follows:

Conclusions
It is time for the writer to draw some conclusions related to the hypothesis proposed in chapter 1 and the testing hypothesis in chapter IV. The writer presents some conclusions as follows: a. Teaching prefixes and suffixes in context can develop students' English vocabulary.
As we have seen from pre-test and post-test result diversities both experimental group and control group that diversity scores averages for experimental group (40) is better than diversity scores averages for control group (30.15). This indicates that developing students' English vocabulary by teaching prefixes and suffixes in context is better than without context.
b. The success of teaching prefixes and suffixes in context depends on teachers' creativity in formulating learning material, indicators and objectives.
c. Teaching prefixes and suffixes can help the students figure out the word meaning and part of speech by recognizing its meaningful unit and base.
d. Understanding which bases and which meaningful units, the students can find out how to form the real words.
e. Teaching prefixes and suffixes can help the students learn how to pronounce the words.

Suggestions
Based on the conclusions above, the writer presents some suggestions as follows: a. To the Teacher 1) In teaching and learning process, teaching prefixes and suffixes in context can be used as one of independent word learning strategies.
2) Some unfamiliar words in reading textbook may contain prefixes and suffixes.
Foreign language teachers can help students derive the meaning of the words by analyzing prefixes and suffixes within the words and context clues around the words such as part of speech, contrast, definition and other clues.
b. To the Readers