TOPIC: Recyclable waste products
At the end of the lesson, students will be able to:
1. Think inductively so that, given a set of examples (recyclable items) and contrasting instances (non-recyclable items), they will identify the defining characteristics of recycling.
2. Identify and categorize the waste products that can be recycled in the United States and those which cannot.
3. Examine recycling availability within their home, school, and community, and give reasons for the need to recycle.
4. Offer suggestions to increase recycling awareness within their community and plan ways in which they can recycle more.
Definition: A Recyclable Item is a waste product, which after original use, can undergo further treatment: ie. breaking up, melting, cleaning, or reprocessing, and can be reused again and again. Most waste products cannot be recycled, so it is important that students be able to identify which items can be recycled to keep waste disposal at a minimum.
Examples: glass (bottle, jar); paper (newspaper, cardboard, white paper); aluminum/tin (soda can, food can); plastic (milk containers, grocery bags)
Concept Hierarchy chart:
Following is the prepared list of initial examples and “non-example” (contrasting instances), and “test” examples. Sample materials for this lesson :
Teacher will explain to the students that they are going to explore an important environmental concept by comparing some examples of the concept with some contrasting instances. Their task is to figure out what the examples have in common, and how the examples differ from the contrasting instances, or “non-examples.”
PHASE I – PRESENTING EXAMPLES
1. Teacher presents different kinds of waste items, one at a time, to the students by holding the objects up in front of the class or walking around the room. Students may touch the objects.
2. Teacher then places each item, as it is shown, on a table next to signs marked “yes” or “no”. Items which are recyclable are placed in the “yes” category and those that are not are placed in the “no” category.
3. Students record the items in the appropriate column on the data sheet and try to determine the concept.
4. Initially, students should work independently (about 5 minutes). Students who know the concept should remain silent and write the answer on the data sheet and add their own examples to the “yes” category (Most students will not be sure or will be incorrect).
5. Following the analysis and testing for understanding of the attributes, a team states the concept. Teacher then shows students the displayed examples and contrasts, and asks them to study them carefully. The class will work together to try to identify the concept.
PHASE II – ANALYSIS OF HYPOTHESES
What are some concepts that differentiate the examples (labeled “YES”) from the contrasting instances (labeled “NO”), that might possibly be characteristics of the concept we are trying to identify?
Teacher lists studentsâ€™ ideas on blackboard (labeled “hypotheses” or “possible characteristics”), using their own words as much as possible. Teacher tries to get several alternative ideas.
6. The teacher adds a few more (2 -3) examples to the tables.
7. Students then work with a partner to list and discuss the common attributes of the “yes” items. They combine their efforts to determine the concept.
8. The attributes of the “yes” items are discussed with the entire class and contrasted with the “no”items.
9. The teams then place the remaining items in the appropriate category and suggest additional items that could be placed on the “yes” table.
CYCLICAL PROCESS (repeating Phase I and Phase II with new data)
10. Add the additional items to the lists (soda can and Styrofoam, grocery bag and diaper).
Given this additional information, what characteristics might we add or eliminate as possibilities from the topic?
Students explain their responses. Teacher crosses out any characteristics that they decide to eliminate, but doesnt erase them.
Teacher puts up list of test examples. Students select examples form list and tell whether they are examples or contrasts. Teacher tells them whether they are right or wrong and add the instances to the proper list. Students describe their thought processes as they were solving the problem.
PHASE III â€“ CLOSURE
When students have isolated the characteristics (criteria attributes) that differentiate examples from non-examples, teacher reviews with them the remaining characteristics to make sure they are all supported by the data. Teacher asks if anyone can name or label the concept. If not, she provides the label. If they suggest other terms that represent the sense of “recyclable items,” she accepts them and adds that the term generally used by environmentalists and the media is “recyclable items.”
Teacher puts the hierarchy chart up on the board, and asks students to identify instances from the given data that fall under each category and sub-category. Students give reasons for these placements.
PHASE IV â€“ APPLICATION
Teacher asks students to add instances to any of the categories or sub-categories from their own knowledge or experience. (eg. students may already recycle at home – share items they recycle.)
What kinds of recyclable items have you used and then actually recycled? Do you think schools could do more to encourage students to recycle more? What could be done?
1. Informal observation:
ï‚· How logical are students in their use of data to test and eliminate hypotheses?
ï‚· How willing are the students to suggest possible concepts?
ï‚· What experience have students had with recycling?
2. Evaluating understanding of the concept, sample measurement question:
ï‚· How important do you feel recycling is in our community?
ï‚· Do you feel more should be done?
ï‚· How can we, as a class, become more active in recycling?