Development of Digital Book in Enhancing Students' Higher-Order Thinking Skill

During the Covid-19 pandemic, the learning process is carried out massively from home, on the other hand, higher-order thinking skills (HOTS) remain a priority for learning objectives, therefore it is necessary to ensure creative solutions to achieve it. Digital book is a learning media that is compiled by combining: 1) text, 2) animation, 3) audio, 4) video, which can be accessed easily and systematically via online. The development of this book aims to facilitate online learning during the covid-19 pandemic, then specifically to measure the level of validity, practically, and effectiveness in increasing students' HOTS. This research was conducted in five stages: 1) analyzing, 2) designing, 3) development, 4) implementation, and 5) evaluation (ADDIE model), while the instruments used were observation sheets, validation sheets, questionnaires, and essay tests. This research was conducted in class E and F, each consist of 35 students. The results of data analysis indicate that this book is in a valid and practical category. Furthermore, this book is very effective to be used to enhance student HOTS.