การสร้างแบบทดสอบวินิจฉัยด้านไวยากรณ์วิชาภาษาอังกฤษสำหรับนักเรียนชั้นมัธยมศึกษาปีที่ 6

Abstract

The objectives of this research are 1) to investigate the grammatical errors in English language skills among grade 12 students, and 2) to construct a diagnostic test for identifying grammatical error in English language skills among grade 12 students. The sample used in the research consists of 982 grade 12 students from various educational institutions, including Basic education schools, Vocational education offices, and other affiliated institutions. The sample was selected using a Multi-Stage Random sampling method, divided into three groups including group 1, 420 individuals, is used to investigate the error and collect incorrect answers to use them as distractor in diagnostic test. Group 2 consisting of 187 individuals, is used for research to assess quality, select, and improve the test items. Group 3 with 375 individuals, is used for reliability and cut-off score. The research tools include: 1) a survey test in the form of completing item and multiple choices for identify the grammatical errors from the response of students, assessing question content alignment and English language grammar based on CEFR standards, with an Item Objective Concordance (IOC) value ranging from 0.6 to 1; and 2) an English language grammatical diagnostic test in the form of multiple choices test with four choices, comprising 65 multiple-choice questions, with statistical analysis including difficulty, discrimination index B, reliability using Lovett’s Method, and cut-off scores for diagnostic purposes following Glass' method. The findings were; 1. Grammar errors in English language skills identified in each behavior indicated by the survey test among grade 12 students revealed a total of 19 errors across 15 indicative behaviors. It was found that students exhibited the highest deficiency in misunderstanding Grammatical Functions of words in English, founded in 13 indicative behaviors. Following this, the next most prevalent error was in misunderstanding the rule of Subject and Verb Agreement in English, founded in 7 indicative behaviors. 2. The results of constructing a diagnostic test for grammatical errors in English language skills for grade 12 students were derived from synthesizing the content of the diagnostic test surveying grammatical deficiencies in English language skills based on The Common European Framework of Reference for Languages (CEFR). The diagnostic test comprised fill-in-the-blank and multiple-choice questions, along with gathering incorrect responses from the surveying test, which were incorporated as distractors in the diagnostic test. Subsequently, experts assessed the alignment between deficiencies and incorrect responses from the surveying test. All questions and distractors were compiled to create a diagnostic test for English language grammar, in the form of multiple-choice questions with 4 options each. There were three subtests: subtest 1 - Syntax rule, with 21 questions; subtest 2 - Predicted verb, with 30 questions; and subtest 3 - Sentence construction, with 14 questions. The content validity index of the diagnostic test ranged from 0.6 to 1.00. The quality assessment results of the entire test showed an average difficulty index ( p ̅ ) of 0.92, an average discrimination index ( B ̅ ) of 0.49, a reliability coefficient (rcc) of 0.96, a standard measurement error (SEmeas) of ± 3.21, and diagnostic cut-off score for each subtest were 10, 12 and 6 respectively. The overall diagnostic test cut-off score was 29 points. The concurrent validity for each subtest were 0.91, 0.94 and 0.95. perspectively. The overall concurrent validity was 0.95