At the same time, the teachers, through allocating the course-related homework, can find the improvement room for their teaching. Actually speaking, the homework is one dispensable part for modern education which emphasizes the effective interaction between students and teachers. Without this seemingly time-consuming process, teachers will have high possibility of losing direction of teaching and students are confused for their learning effectiveness.

Therefore, the effectiveness homework design is very important.

1.4 Definition

1.4.1 Homework

Homework first appears in German schools in 1505. When teaching is shifted from inpidual teaching to classroom teaching, homework becomes the continuation of the teaching job and also becomes a means for students to conduct study inpidually. (钱萍, 2012) Then what is homework?

Originally, the concept of “homework” was used in physical labor, refers to the tasks that workers should do after work or outside the factory (赵雪梅，2013). But applied to the field of education, it refers to tasks assigned to students by their teachers to be completed outside the class (Wikipedia). In The Note of Learning，the first theoretical works to discuss systematically and carefully about the teaching of education, has some remarks about homework. Former Soviet educator N. A. Kaiipob thinks homework is a component part of instructional work, which is the mission to work independently with a method to consolidate students’ knowledge, and to improve students' skills and techniques fundamentally. Since the 1980s, most of education reference books published in China adopted the concept of Kaiipob’s view of homework to define homework, such as Dictionary of Practical Education considers that “homework is the learning activity that students independently do in order to complete the learning assignment” (Wang, 1995:697). Similarly, Oxford Advanced Learner’s English---Chinese Dictionary states homework as “ 1) work that is given by teachers for students to do at home 2) (informal) work that somebody does to prepare for something”. (2011,78) Besides, American scholar Harris Cooper's definition is widely accepted in homework research field. He regards homework as "tasks assigned to students by school teachers that are meant to be carried out during non-school hours" (Cooper, 1989:7).