Rina Hilmina. 2024. The effect of Using Quizizz Application on the Vocabulary Size of Eighth Grade Students at SMPN 30 Banjarmasin. Sarjana’s Thesis. English Language Education, Lambung Mangkurat University, Banjarmasin. The first advisor: Dr. Novita Triana, S.Pd., M.A., the second advisor: Emma Rosana Febriyanti, M.Pd.

Keywords: Quizizz Application. Teaching Vocabulary, Vocabulary Size.

Vocabulary is a fundamental aspect of language learning, playing a crucial role in students’ ability to comprehend and express ideas. At SMP Negeri 30 Banjarmasin, many eighth-grade students demonstrated low vocabulary size, as reflected in an initial test with an average score of 33.2, indicating that their English proficiency was still below the expected level. Therefore, this study was conducted to determine whether the use of the Quizizz gamification-based application can have an effect on increasing the vocabulary size of eighth-grade students at SMP Negeri 30 Banjarmasin.

This research employed a quantitative approach with a quasi-experimental design. The participants were eighth-grade students divided into two groups: an experimental class taught using Quizizz and a control class taught using Wordwall. Both groups received treatment over four sessions, each focusing on different vocabulary themes. The data were collected through a pre-test and post-test consisting of multiple-choice questions covering synonym, antonym, word meaning in context, and word definitions. The results were analyzed using statistical tests of SPPS 21 version.

The results showed that the average score of students in the experimental class increased from 45.74 to 68.58, representing a gain of 22.84 points. In contrast, the control class experienced a 21.39-point improvement. Although both classes showed progress, the experimental class achieved a higher increase, indicating that the use of the Quizizz application was more effective in enhancing students’ vocabulary size. This conclusion was further supported by the results of the independent sample t-test, which showed a significance value of 0.04 (< 0.05). Therefore, it can be concluded that Quizizz has a statistically significant effect on students’ vocabulary size.