Introduction
Part -1 - Designing and building the water purifier.
Hook/Problem situation: The area you are staying in, is not getting water supply from municipal corporation. You have to use the water available in the nearby pond. But the water in the pond is polluted. It is seen turbid and one can see various plants and hydrophytes growing in it. You have to make use of this water for all your needs. Basically you have to make it potable.
Students are going to take up a dual role. They are going to be environmentalists as well as engineers in R&D of the company making water purifiers. The teacher conducts following activities while implementing DBL:
1. Teacher divides the class into teams of 5 students in each team.
2. They are provided with the hook and asked to find the solution to the problem.
3. Teacher asks them to discuss the ways of purification of this water and prepare sketch of a water purifier.
4. They discuss various constraints, Requirements, & models.
5. They discuss different ideas to design the water purifier. In groups, they first make sketches of water purifiers and give suggestions to each other.
6. They make a list of materials required.
7. Teacher provides them the required materials and sufficient time to prepare the prototype of water purifier.
Part -2 - Testing and redesigning
1. Orient students that they will test the Water purifier prototype to see how it works and remove the problems it may have by modifying the design.
2. They need to modify the design according to their results and retest until they reach a final solution that works (The potable water).
3. Get students to test their purifiers.( Test the purity of water with some set standards- they can do assessment of quality of water)
4. Following which each group makes observations in their workbook.
5. Inform the students that they have to conduct minimum 3 trials with the prototype.
6. Give each group time to discuss the performance of the prototype.
7. Based on observations, sketch 2 ways they can improve their design to get better results.
8. Students after making necessary changes, finalize the design.
Part 3 – Presentation
Have the students present their final design and evaluate other teams’ design
1. Provide students time to make a presentation of their water purifiers. They show the sketch of the purifier as well as they demonstrate the functioning.
2. Orient students on the timeline and the roles for each student.
3. Students present their prototypes.
4. Open discussion which is led by the teacher
5. To conclude ask the students to fill the summative questions in the workbook
Culminate the project by asking students to reflect on the entire design process. Have students fill in the L column of the K-W-L chart and share the same with the entire class