In English vocabulary learning, continuation is an important factor; however, many learners are not good at continuing learning because they tend to prefer amusement or rest. Our proposed system is targeting learners who are eager to learn but are not able to continue learning for various reasons. We especially focused on English vocabulary learning, and described an approach for learners who have difficulty with continuing learning. Our developed application aggressively supports the learners' sustainable motivation by gamification techniques and an efficient difficulty setting method.
Keywords: Gamification; Sustainable motivation; Vocabulary learning.