Science Introduction
A Model for Problem-Centered Science Units
When introducing new conceptual knowledge to young learners, it is wise to link it to concepts they have already encountered. And still wiser to give reasons why this new knowledge has value for them. One of the best ways to do both is to use items that are readily available in the learner's personal environment.We will show an example of how the science process skills of observing, predicting, inferring, and forming hypotheses can be achieved using paper towels. Two preservice teachers will go into a seventh grade math classroom and present this lesson under the direction of the regular teacher. It invites students to start with a simple problem: "Is there any difference among four brands of paper towels in terms of their wet strength and absorbency?"
The students devise their own test for these two variables, and use it to rank common brands of towels. In the process they practice what science is all about - seeking answers to questions using rules of fairness and logic.
After working in teams to apply their tests, students compare their results of the ranking of paper towels by wet strength and absorbency. If these results differ, they must decide what additional tests or modification of their current tests would be appropriate to achieve more reliable results. This is an excellent model for science thinking.
It also provides a fine example of good teaching strategy - put the learner in control of examining concepts and then ask the learner to explain results in terms of conceptual frameworks as modified by new experiences.
Let's take a look at problem centered teaching and learning in a middle school science classroom.