COMPUTERIZED ADAPTIVE TESTING IN LANGUAGE EDUCATION OPPORTUNITIES AND CHALLENGES IN ERA 4 0 Bui Thi Kim Phuong (Hanoi University of Science and Technology) Nguyen Quy Thanh, Le Thai Hung (VNU University of Education) Abstract Computer technology is being widely applied in education in general and in assessment in particular, especially in the 4 0 era of digital transformation In the field of language education, computerized adaptive testing (CAT) is not a new concept and has attracted increasing[.]