Enhancing of Students ’ Learning Outcomes in the Environment Pollution Concept through Project Based Learning ( PjBL )

This study aims to improve the learning outcomes with the use of Project Based Learning (PjBL) model on the concept of environmental pollution. The research method used was Classroom-based Action Research (CAR) conducted in two cycles. Each cycle consisted of planning, implementing, observing, and reflecting. The subjects of the study were the students of class X MIPA 1 SMAN 9 Tangerang Selatan in academic year 2016/2017 with the number of students was 38. The research instruments used were test and non-test instrument. Instrument test was in the form of multiple choices (30 questions), while the non-test instruments were in the form of observation sheets and field notes. The data analysis technique was by using N-gain test. The result of this research showed that the improvement of learning outcome in the concept of environmental pollution with the use of learning model based learning (PjBL) in each cycle was 47.37% in the cycle I, and 94.73% in the cycle II. The learning activity of the students showed the increase of activity with the use of learning model Project based learning (PjBL) in the cycle which was 72% in cycle I, and 78% in cycle II. The result of N-gain analysis showed the increase of N-gain from pretest to posttest in which the average of N-gain value in cycle was 0.32 in cycle I and 0.53 in cycle II. Thus it can be concluded that there is influence from the application of the model of Project Based Learning (PjBL) to improve student learning outcomes on the concept of environmental pollution.


INTRODUCTION
The concept of environmental pollution in class 10 of high school is in the subject of environmental change.
According to the High School Biology syllabus guidelines (Kemdikbud, 2016) it is suggested that the learning activities

Create a Schedule
Stage when the teacher and students collaboratively arrange the activity schedule in completing the project.

Progress of the Project
The teacher is responsible for monitoring the activities of students while completing the project.

Assess the Outcome
Assessment is carried out to assist teachers in measuring the achievement of standards and learning objectives.

Evaluate the Experience
The teacher and students reflect on the activities and final results of the project that has been carried out.
The use of the PjBL model can provide benefits for students, teachers, and the development of school quality, as mentioned below (Railsback, 2002) Create a Schedule  The teacher facilitated the students to schedule activities that referred to the maximum agreed time. The teacher facilitated the students to arrange alternative steps, if there were sub-activities that exceeded the scheduled time. The teacher askeds each group to write down the reasons for each choice chosen.

Monitor the Students and the Progress of the Project
 The teacher monitored the activities of the students while completing the project Assess the Outcome  The teacher conducted assessments during monitoring carried out by referring to the assessment rubric  The students presented projects in the form of posters that have been made Evaluate the Experience  The students in groups reflected on the activities and results of the projects that have been implemented.Then another group was asked to respond.

Student Learning Outcomes
From the results obtained, the average learning outcomes after the application of PjBL learning to the concept of Environmental Pollution showed an increase on Figure 1.there is an increase in the value of student learning after using the PjBL learning model and it can be seen in Table 2.

Results of Observation of Studen t Learning Activities
Based on the results of observation of learning activities in the first cycle and second cycle, it is known that there was an increase in the student learning activities and it can be seen on Figure 3.This shows the activity and response of students were quite good by using the PjBL learning model.

Figure 3. Student learning activities
The results of previous studies indicated that PjBL learning models can improve cognitive learning outcomes (Mahanal et al, 2010;Insyasiska, Zubaidah, and Susilo, 2015).Similarly, in this study the same results were obtained.
The increase in learning outcomes is due to the benefits of applying the PjBL Based on the analysis, the N-gain value has increased from cycle I to cycle II, which is from 0.32 increasing to 0.53 with a medium category.

REFERENCES
and recycled products.(2) Conducting water / air pollution experiments or make recycled products.(3) Discussing experimental results and causes, ways to prevent, how to cope with global warming, depletion of the ozone layer, greenhouse effect, activities of human activities, concluding and presenting with various media.(4) Making a campaign about the impact of climate change, efforts that can be done and present the results of recycled products.Based on the results of the preliminary study through interviews with biology teachers, it is known that in the last two years, namely in 2015 and 2016, the learning concept of environmental pollution is usually used the assignment method.In the assignment, the students are asked to read the subject themselves and make waste recycling products with the assignment time of 2 weeks.The first reason for applying the method is because it often lack face-to-face learning time.The second reason is to assess this concept as an easy concept so that students are considered capable of understanding it themselves.With the application of learning, learning outcomes are usually obtained with an average value of 70 (according to Minimal Completion Criteria).

Figure 1 .
Average Student Learning OutcomesIn the first cycle, the average value of learning outcomes was 71.26 with the
the beginning, the students must first understand the content of the concept of environmental pollution and its impact on the environment, then ended with presenting efforts that can be done to prevent environmental pollution as outlined in a poster.Secondly, the students learned to collaborate with each other in solving the problems appeared; the students in working on projects given namely posters and waste recycling products work in heterogeneous groups collaborated with their group friends to solve the problems given.In this case, the students proposed environmental preservation efforts and producing a product that was recycled waste, in this study the waste used was newspapers.The products were produced by various types of products, for example pencil cases, frames, piggy banks, mailboxes, and so on.Third, promoting independent learning as students assume greater responsibility for their learning; students in PjBL learning independently, starting from designing project planning to evaluate experiences.Fourth, PjBL involves various types of tasks, so as to fulfill a variety of student learning styles, : students in carrying out the given project certainly carry out a series of activities that are in accordance with various learning styles, ranging from visual, aural, read / write, and kinesthetic.CONCLUSION Based on the results of classroom action research conducted in class X MIPA 1 of SMAN 9 Kota Tangerang Selatan, it can be concluded that the application of the learning process given by the teacher to the PjBL learning model can improve student learning outcomes on the concept of environmental pollution.This is due to an increase in learning outcomes from cycle I to cycle II.In the first cycle, students who achieved the Minimum Completion Criteria were 18 people (47.37%) and increased in the second cycle to 36 people (94.73%).