The Effect of Using Quizlet Toward Students’ Vocabulary Mastery

The aim of this research was to know if there is significant effect of using Quizlet toward student vocabulary mastery. This research was using quasi-experimental research with two types of variable. First variable was the application of Quizlet as the independent variable while the second variable was the vocabulary mastery as the dependent variable. The samples in this research are students of eleventh grade at SMA Negeri 2 Trenggalek they were MIPA 2 as experimental group and MIPA 5 as control group. The experimental group was using Quizlet as learning media while the control group was not. The instrument was to collect the data of this research by pre-test and post-test. After the data was collected, the researcher analyzed the data by using independent sample t-test. Based on test the Sig. (2-tailed) of post-test were 0.000 <0.05, than as the basic rules of making independent sample t-test, it can be concluded that H 0 is rejected and Ha is accepted. Thus, it can be concluded that there is a significant difference between the average student learning outcomes in the experimental group and the control group. So, Quizlet application is an effective learning media for students' vocabulary mastery


INTRODUCTION
Language is structured tool and has meaning that is free of its users in education. One of the languages used by many people in a lot of countries in the world is English. English is the most dominant foreign language used starting from basic education to higher education. According to Setiawan (2010:1) there are four components of language skill in English, covering; reading, speaking, writing and listening that should be learned by the learners appropriately and deeply.
To be able to use English they must be master of vocabulary. Hotimah (2010:12) argues that vocabulary is a set of words that are understood or words that are going to compose a new sentence. Thus, vocabulary is an essential thing for those who learn a language. They should master vocabulary because it is one of the most important components of English. To make students be master vocabulary and they feel that learning vocabulary is fun the teacher should teach by using interactive learning media.
Nowadays, the teachers need media to support their teaching activities. Based on the character of the student, they need interactive learning media. It is significant to apply technology as media in learning and teaching process without the limitation of time. One of the interactive media application in learning English is Quizlet.
Quizlet is an online application that enables to access any subject, anywhere and anytime. Quizlet as learning media provides some useful contents developed by a high school student in California, Andrew Sutherland. This design is originally designed in 2005, but released to the public in January 2007 in the form of a website. Furthermore, in August 2012 Quizlet was released in the form of a mobile application for iOS then following released for android in August 2013.
Quizlet give user access to a database with millions of flashcards ready for use. The device allows groups to be created, allowing students to work and communicate within their group. As a powerful study tool, it offers four modes of learning; flashcards, speller, learn, and test. It also allows you to play competitive games, such as scatter and space race.
Quizlet provides a wide range of lesson materials. Also Quizlet can be an Assessment tool to follow student progress. The teacher creates a set of lesson material with the following steps: 1. Create e new user account; 2. Make flashcards to create a new set, enter the title, subject, and description; 3. Set access levels for user and editors; 4. Insert the terms and corresponding definition, and click on create set.
Students can access any subject, anywhere and anytime by using Quizlet.
There are four tools to student easily learning English with Quizlet: The problem based on the background above, the researcher focus on using Quizlet as a learning media toward the students' vocabulary mastery. Formulation of the problem according to the explanation above is formulated as follow; is there any significant effect of using Quizlet toward students' vocabulary mastery? The purpose of this study was to know if there is significant effect of using Quizlet toward student vocabulary mastery.

METHOD
This research was conducted by using Quasi-experimental as a design of experimental research. This design is suitable for researchers who wanted to know the effect of certain treatment on others. In this research there were two groups, namely experimental group and control group. The experimental group was given treatment by using Quizlet, while the control group was taught without using Quizlet.
According to research design, the researcher used three procedures to conduct this research they were giving pre-test, treatment and post-test. The tests were validated by the expert before given to the students. Pre-test were given to the both group (experimental and control group) to know their achievement before the treatment.
After that, the experimental group was given treatment by using Quizlet and the control group was taught as usual without using Quizlet. Finally, the researcher compared the result of both groups were there is an effect by using Quizlet or not.
The population of this research was the eleventh grade students at SMA Negeri 2 Trenggalek. In this research, the researcher took two classes. They were one class as an experimental group and one class as control group. The researcher used cluster random sampling technique. According to Sukardi (2012:61) the selection of the group based on their group, region or groups of subject who naturally gather together. The researcher conducted this research at eleventh grade MIPA of SMA Negeri 2 Trenggalek consist of two classes with the steps in determining the experimental and control group are follows: (1) The researcher made a lottery based on the classes, and then put it into the glass. (2) The researcher shook the glass and took two lotteries, which came out first as an experimental group and then the last as control group. (3) The class who received the lottery was XI MIPA 2 as an experimental group and XI MIPA 5 as a control group.
In this research there were two types of variable, namely independent variable and dependent variable. Quizlet as independent variable is going to give effect to dependent variable. Students' vocabulary mastery as dependent variable is going to get the effect from independent variable. The researcher used students' achievement score by using test before and after given the treatment to know their vocabulary mastery. The test used in this research were pre-test and post-test. The result of pre-test and post test analyzed in order to know the effectiveness of using Quizlet toward students' vocabulary mastery. This research used vocabulary test as tool for testing in order to know students' vocabulary mastery. This research was used pre-test and post-test. There were 25 questions of multiple choices.
There were three tests that must be done before analyzing the data by using independent sample t-test, namely validity test, normality test and t-test. The most complex criterion in a good test is validity, the extent to which inferences made from assessment result are appropriate, meaningful, and useful in terms of the purpose of the assessment, Fathony (2017:17). Content validity is a non statistical type of validity that involves 'systematic examination of the test content to determine whether it covers a representative sample of the behavior domain to be measured or the extent to which a measuring instrument provides adequate coverage of the topic under study. If the instrument contains a representative sample of the universe, the content validity is good; its determination is mainly judgmental and intuitive (Shadish et al, 2002). It was also determined by using a panel of persons who shall judge how well the measuring instruments meet the standard, but there are no numerical ways to express it. In order to establish this, in this research, experts had been consulted. These consultations ensured that the test item prepared for the students has sufficient content validity.
Normality test used to analyze the sample of population from experimental and control group are normally distributed or not.

Finding on Validity Test
The experts of this content validity was English teacher at SMA Negeri 2 Trenggalek, Mr. Aris Stiawan, M.Pd. Considering his expertise and experience, his assessment and suggestion are considered to be valid. The researcher arranged the question of the test based on trusted source. After all the items marked and resulted good, the learning materials then claimed valid although there were some revisions and suggestions from the expert.

Finding on Normality Test
This test is used to analyze the sample of population from experimental and control group are normally distributed or not. The analysis of normality test is as follow:

Finding on t-test
T-test for pretest and post-test of experimental groups were used to find out how the effect of Quizlet toward students' vocabulary mastery. These were the results of pretest and posttest t-test experimental groups using paired sample t-test:  Based on the "Paired Sample Statistics" experimental group above, it is evident that the value of "Mean" in the posttest is higher than the pretest. From the table above it can be seen that the significance value (2-tailed) of this research is 0.000 (p <0.05). So, the results of the experimental groups pretest and posttest have significant changes. Meanwhile, to find out the difference vocabulary mastery between experimental group by using Quizlet and control group using conventional methods.

Discussions
To know whether there is or there is no significant effect of using Quizlet toward students' vocabulary mastery, the researcher compares the score post-test of experimental and control group by calculates t-test.
The hypothesis (Ha andH0) explained in the following statements: Ha = "There is a significant effect of using Quizlet toward students vocabulary mastery" H0 = "There is no significant effect of using Quizlet toward students vocabulary mastery" Based on the "Independent Samples Test" the Sig. (2-tailed) of posttest are 0.000<0.05, then as the basic rules of making the independent sample t-test, it can be concluded that H0 is rejected and Ha is accepted.
Based on the result of this research, interactive learning media is effective way to teaching students especially students of senior high school who has lack of learning motivation. According to Azhar (2011) learning media is a tool in learning process both inside and outside the classroom. Quizlet is an online application that enables to access any subject, anywhere and anytime. Besides that, Quizlet as learning media provides some useful contents such as flashcard, writing, spelling and quiz or test.
In addition, Muttaqien (2017:26) states that "many students do not like English and they have not been able to communicate because their lack of vocabulary mastery". Using Quizlet helped the students enjoyed learning vocabulary and considered Quizlet as useful and beneficial tool for their learning development, particularly in vocabulary learning.

Conclusion
Based on the previous chapter, the result of this research can be concluded that there are any significant effects by using Quizlet towards students' vocabulary mastery.
Applying Quizlet in learning English in senior high school is the right choice for the teachers, where in using that application the teacher can see the progress of the class whether students have studied the material provided. It can be proven by the findings that the mean of the post-test scores was higher than pre-test. The mean of the posttest in control group was 78.5 while the mean of post-test in experimental group was 89.5. Quizlet is a language learning media that can be used to increase levels of active learners. It is one of the effective media in teaching-learning vocabulary for students.

Suggestion
There are some suggestions for people who find some benefit of this research after the researcher conducted this research. First, Quizlet is the application that can be accessed anywhere and anytime and any situation, so the teachers did not difficult to implement their materials. Second, Quizlet helps the students find new vocabulary by learning any set in that application and also make the students memorize vocabulary well by the picture in that application. The last is for the next researcher who may use the research finding of this research as the information and reference for their research.