Teaching in Electronics using Group Investigation Model By Ade Setiawan

Description
I have been working as a teacher for about five years. I teach electronics engineering in SMK Negeri I Batam (Batam Vocational School). The subject that I teach is “Electro-Mechanical Practice” for 16 years old students. One of the topics in this subject is to make an individual project and this project usually do at second semester. The project is to make an Adjustable Power Supply where student must develop the power supply by him/herself from beginning (casing designation) until the power supply ready to use. Adjustable mean that the output voltage of the power supply can vary and set from 0.5 up to 18 DC Volt.

The development of this project divides into two parts:
o Mechanical work
o Electronics work
Mechanical work consists of casing design, draw on the flat, flat cutting, flat drilling and folding. Meanwhile electronic work consist of layout design, draw lay out on PCB (printed circuit board), etching, cleaning, drilling, soldering (mount electronics component into PCB) and finally assembly the PCB with component into casing.

The next step of this project is to do testing. The purpose of the testing is to make sure that the power supply being developed can produce certain output voltage as stated in product specification. In this case the product specification of the output voltage is vary from 0.5 – 18 DC Volt. Testing is one of the critical processes during accomplishing this project, because if the result is not in line with the specification its mean that “there is something wrong” with the power supply. Based on my past experience, in every class only 10 - 15 % of the students that can directly success to get the result as per specification, the rest must do investigation.

The symptom that appeared during testing process i.e: output voltage is out of specification -either lower or higher-, no voltage at all, no signal at indicator or LED (Light Emitting Diode), the output voltage cannot be adjusted or even the circuit getting burn when the switch is ON.
As a teacher we must help the student to find the root cause of the problem but we cannot help them directly without give student a chance to think and do an investigation by his/herself first.

Group Investigation teaching model is the most suitable approach in such case. Teacher as a facilitator must make a plan or a scenario rather then help student one by one to do an investigation. The scenario is to make group investigation. If the total student in the class is 40 and there are 5 students that already finish their job, it means that can create 8 groups to do group investigation. Each group consists of 5 students and the students who finish their job can be appointed as the leader of each group. So each group leader must help 4 students member in his/her group to find out the root cause why their supply cannot work.

As a teacher we can give some guidance to them on how to do electronics problem solving or investigation. For instance, we can ask them to investigate or check the voltage at input part first. If no fault found on the input, the investigation can proceed to the next part. Also the teacher must able to create the climate of competition among the group, for example can give special award to those that accomplished their job faster than the others. To make sure that all team members are understood about the investigation process, we must ask them to make report once they finish their job. The report must able to explain of each process during investigation based on their finding and how they can find root cause.

After the entire group accomplished their group investigation with a list of finding, I as a teacher ask each member to resume their finding and explain the process how to solved it and present to the other group. During presentation, the other group must pay attention and they have a right o interrupt in case they find something “clumsy” or different with their finding in the case of similar symptom. This discussion session will help student to verify their finding and also every student can learn from other group finding. So there is a cross-fertilization process among the group.

Evaluation
The effectiveness of this group depends on the role of the teacher, leader, and group member. Effective mean that the group can work together as per plan by the teacher, can meet the objective of group investigation and also can fulfill the time frame that have been set. In order to maintain the effectiveness, I as a teacher must able to identify the role and responsibilities of each component:

o Teacher
During the group investigation, the teacher must monitor the whole process and pro actively intervene if the group found difficulties. The teacher must able to identify the problem on each group and give a new guidance if the leader and all team members stagnant. This is to make sure that group investigation can running well, consistent and focus to the goal and objective.
o Group leader
The role of a group leader is also very important. Beside s/he must having better knowledge and trouble shooting skill, s/he must have leadership skill. S/he must able how to lead their team member, organize and manage the activities.
o Team member
Meanwhile, all the team member must involve actively and able to give contribution during the investigation process, not just sit down and observe the work of his/her friends.

Based on my experience the group investigation in power supply development problem can give satisfaction result and much faster than individual trouble shooting, because during group investigation the students can exchange their knowledge, skill and experience. The discussion among them can reduce time of problem solving. The experience of one student about the already known symptom can reduce time, because the group no need to do further analysis by measure voltage at certain point. The investigation question such as why the LED indicator is dimmer, why the output voltage cannot be adjusted and so on sometimes not always necessary to be measure using volt meter, but experience of the other can –sometimes- can help to solve the problem.

In certain case, sometimes two students at the same group having the same symptom. It can reduce time consumption, one investigation for two devices all in once. The students also can learn not just on his/her problem, but from the others. This condition can be an advantage for them as learning process enrichment, especially in field of electronics trouble shooting.

Implication
After I have experienced on this teaching model for about five years, I can take a lot of values and advantages especially in view of the benefit of student and learning process:
o It can thrift time when doing group investigation compare to do individual investigation as I explained in previous paragraph. So group investigation is more effective and efficient.
o Develop social, interpersonal and team work skill, because during group investigation the entire group member must involve in intense communication, how to convey his/her opinion and how to accept others opinion.
o Thinking practice based on scientific inquiry. Even the student can assume this or that during the group investigation, but their assumption must prove with the scientific inquiry. Even there is a social interaction among them, but they should realize that they are learning the exact things, whatever the finding must based on scientific approach (measure, test and check).
o Provide an experience-based learning situation, because the student can learn from the other experiences and this situation will enrich their knowledge and skill in a very short time. S/he can find a lot of finding without need to explore all by his/her selves.