The Effect of Contextual Teaching and Learning Combined with Peer Tutoring towards Learning Achievement on Human Digestive System Concept

This research aims to know the influence of contextual teaching and learning (CTL) combined with peer tutoring toward learning achievement on human digestive system concept. This research was conducted at one of State Senior High School in South Tangerang in the academic year of 2016/2017. The research method was quasi experiment with nonequivalent pretest-postest control group design. The sample was taken by simple random sampling. The total of the sampels were 86 students which consisted of 44 students as a controlled group and 42 students as an experimental group. The research instrument was objective test which consisted of 25 multiple choice items of each pretest and posttest. The research also used observation sheets for teacher and students activity. The result of data analysis using t-test on the two groups show that the value of tcount was 2.40 and ttable was 1.99 on significant level α = 0,05, so that tcount > ttable.. This result indicated that there was influence of contextual teaching and learning (CTL) combined with peer tutoring toward learning achievement on human digestive system concept.


INTRODUCTION
National Education works to develop the skill and the character formation and civilization of a dignified nation in order to educate the society, for the growing potential of learners to become believers and to be devoted to God Almighty, noble character, healthy, knowledgeable, capable, creative, independent and become a democratic and responsible citizen (Depdiknas, 2003).
Education is also an important capital for the development of a nation and national educational objectives.
Educational objectives which means the ultimate goals to be achieved by all educational institutions, including formal, non-formal, and informal in Indonesia.The important factors to achieving it, is through the learning process (Widoyoko, 2009).
The learning process involves two activities in one time with different actors.The learners are student while who teaches are teachers.Student and teachers activities takes place in the same process to achieve certain instructional goals.The learning process occurs when there is an interactive communication between teachers and students which tied by instructional goals.Thus, the success of the learning process is depend on teachers and students itself.
Teacher involvement in learning process gives a big influence on the process and learning achievement of students.However, teachers effort in the learning process sometimes can't improve student learning achievement optimally.Therefore, a teacher is to master the approaches and methods of teaching.The use of appropriate approaches and methods in teaching will make it easier for teachers to teach a material.The right approach and method depends on the characteristics of the material to be taught (Zulfiani, et al., 2009).
Biology as one fields of science provides a variety of learning experiences to understand the concepts and processes of science.These process skills include the ability to observe, propose hypotheses, use of tool and material properly and correctly by always considering security and safety.
In addition, process skills also include The learning process with CTL involves the various talents of learners in the process of discovery (inquiry).
This involvement can be maximized by exploiting the potential of self-learners.
Learners who are considered capable (complete learning) can be used as tutors for their friends who is a slow learners (unfinished learning).In addition, the application of community learning principles in CTL can be done by applying learning through study groups.
Students learn each others in groups.
Students who have a certain ability are encouraged to help slow learners.or generic or both.In addition, their interaction may be guided by the provision of structured materials, amongst which a degree of student choice may be available (Topping, 1996).
Learning process with peer tutoring is expected to be easier to understand the concept.Learners do not feel reluctant, inferior or embarrassed to ask for help.Learners will feel satisfied if they can solve the problems.
Therefore, with peer tutoring learning objectives could achieved optimally.
This active involvement can facilitate students to solve problems and learn the subject matter (Jusniar, 2009).Peer tutoring are able to create cooperation among learners.Thus, a positive learning environment is built without putting aside the teacher's duties as a facilitator in the learning process (Sumarli, 2015;Grubbs & Boes, 2009).
Previous research has shown that contextual learning with peer tutoring has a significant effect compared with direct learning on biology learning achievement of students (San, et al, 2013).Thus, the CTL approach combined with peer tutoring can be actively involve students better.
Students are able to make the connection between knowledge possessed and its daily life application.
Learning materials are tools to achieve a learning objectives.One of the learning materials in biology is the digestive system concept.This concept is an interesting material and closely related with daily life of students.
Students can learn about dietary substances, digestive organs, nutritional intake, and the food digestion process that is closely related with dietary habit and the calorie needs.However, in its application this concept is considered quite difficult to understand by students.
The difficulties felt by students is to remember the terms and explain the process of digestive system that occurs inside human body.However students need not only an ability to memorize, but also a high understanding (Sajerah, 2013).The purpose of this study is to determine the effect of CTL approach combined with peer tutoring toward learning achievement on the digestive system concept.

METHOD
The method used in this study is Hypothesis testing is done after the normality test using Lilifors Test, and homogeneity test using Fisher test.
After the data is declared normal and homogeneous distribution, it is continued with t-test.The data observed tabulated then described.

RESULT AND DISCUSSION
Data from pretest of control and experiment class can be seen in Table 1.The data from posttest of control and experiment class can be seen in

CONCLUSION
The results showed that there was a significant difference between the learning achievement of control (79,18) and experiment class students (83,14).
These results indicate that the learning achievement of students in the experimental class with CTL combined with peer tutoring higher than the control class that uses a scientific approach.Thus, it is evident that learning with CTL combined peer tutoring influence on the learning achievement on the human digestive system concept.
Peer tutoring is characterised by specific role taking: at any point someone has the job of tutor while the other(s) are in role as tutee(s).Peer tutoring typically has high focus on curriculum content.Projects usually also outline quite specific procedures for interaction, in which the participants are likely to have training which is specific group design.The sampling technique was done by using simple random sampling.The sample in this study is the students of class XI in one of the public high school in South Tangerang, odd semester of the year of teaching 2016/2017, two classes was taken, namely class XI-MIA 5 as the control class and XI-MIA 4 as the experimental class.This study uses the learning achievement test instrument and observation sheet of the learning process.The test used is a 25 questions of multiple choice test.Observation sheets are used when the teachinglearning of digestive system concept using CTL approach combined with peer tutoring is in process.In addition, this observation sheet is used to determine the extent to which the application of learning approaches during the learning process takes place.
peer tutoring is able to provide learning activities for students to find, process, and find concrete learning experiences (related to JPPI, Vol. 3, No. 2, November 2017, p. 101-111 Abadiyah, et al e-ISSN 2477-2038 110 real life situation) through the involvement of students trial activities, doing and experiencing themselves with the help of students who act as tutor.This research is in line with the results of previous research which found that the contextual approach through the learning community has an effect on the students' cognitive learning achievement in high school (Irwandi, 2013).In addition, peer tutoring can enhance the learning activities and learning achievement in biology (Mbatu et al., 2013).Thus, the results of this study showed that learning with CTL combined with peer tutoring positively affects the learning achievement of students.

Table 1
Pretest Data of Class Control and Experiment

Table 2
Posttest Data of Class Control and Experiment

Table 4 t
-test result of Pretest-Postest Data Control and Experiment Class