Paper Title
Web-Based Instruction of Thai Language in Topic of Vocabulary for Primary 5 Students

Abstract
This research aims to 1) to develop a web-based instructional program to effectively meet 80/80 criteria. 2) to compare learning achievement with web-based lessons before and after learning. 3) to find students’ satisfaction of web-based teaching. The samples were 40 Primary 5 students at Innovation Demonstration School of Rajamangala University of Technology Thanyaburi who are studying in academic year 2018. The method for this sampling is Cluster or Area Sampling which was used to analyze the data by using basic statistics and t-test. The results of this research are 1) the results of the analysis of the effectiveness of web-based teaching in Thai language showed that the web-based instructional program was 82.07 / 81.00. The result was that the web-based computer course was created to be effective and suitable for the students. 2) Web-based learning achievement in Thai language after learning with Web-based instruction is higher than before studying 3) The results of student satisfaction evaluation of the content of the web-based teaching assistants in Thai language is divided into 4 sections. The mean score was 3.52, which shows the highest satisfaction level. The mean score for design was 3.42, which was very satisfied. The means score of presentation style was 3.52, which is satisfied, and the means scores for the important and benefit was 3.67, which is the highest level of satisfaction. Index Terms— Web-based Instruction, Thai Vocabulary, Language Teaching.