  Machine reading comprehension has been an interesting and challenging task in
recent years, with the purpose of extracting useful information from texts. To
attain the computer ability to understand the reading text and answer relevant
information, we introduce ViMMRC 2.0 - an extension of the previous ViMMRC for
the task of multiple-choice reading comprehension in Vietnamese Textbooks which
contain the reading articles for students from Grade 1 to Grade 12. This
dataset has 699 reading passages which are prose and poems, and 5,273
questions. The questions in the new dataset are not fixed with four options as
in the previous version. Moreover, the difficulty of questions is increased,
which challenges the models to find the correct choice. The computer must
understand the whole context of the reading passage, the question, and the
content of each choice to extract the right answers. Hence, we propose the
multi-stage approach that combines the multi-step attention network (MAN) with
the natural language inference (NLI) task to enhance the performance of the
reading comprehension model. Then, we compare the proposed methodology with the
baseline BERTology models on the new dataset and the ViMMRC 1.0. Our
multi-stage models achieved 58.81% by Accuracy on the test set, which is 5.34%
better than the highest BERTology models. From the results of the error
analysis, we found the challenge of the reading comprehension models is
understanding the implicit context in texts and linking them together in order
to find the correct answers. Finally, we hope our new dataset will motivate
further research in enhancing the language understanding ability of computers
in the Vietnamese language.
