Developing a Standardized English Proficiency Test Based on the CEFR and Language Test Development Manual

This study was conducted to construct a Council of Europe Common European Framework of Reference-aligned Standardized English Proficiency Test which is reliable and valid. It utilized the instrument development research design participated by 217 students at Christian University of Thailand during the second semester of Academic Year 2024. The actual test material was made based on the Council of Europe’s (2011) Manual for Language Test Development and Examining with its four major stages: planning, designing, try-out, and informing stakeholders. Items of Listening and Reading test were adopted from the existing references and examination utilized by the university. The findings revealed that the English Proficiency Test was valid with ds=0.35 – Listening Test, and ds=0.35 – Reading Test both in moderate level. The test reliability result was r=1.35>0.05. Therefore, the test can be considered good and valid since the committee carefully designed and considered the processes of development aligned Council of Europe’s (2011) Manual for Language Test Development and Examining.