Giving students opportunities to do experiments and explore the world is important on many levels. It helps them build their science practices. It helps them understand the nature of science and it is a powerful way to teach science content. Also students come up with the most amazing ideas and sometimes surprise you. During my unit on fast plants I let the students choose the experiments they wanted to conduct. Similar to previous years students chose to change the amount of fertilizer, crowd the plants, alter the duration of light, and prevent the test plants from being pollinated. When students suggested changing the temperature we talked as a class about variables and whether we could ensure that the other variables would not be changed. In fact one group argued that if you crowd the plants then to be a fair test you should give them an equivalent amount of fertilizer per plant. Others students argued that the fertilizer is based on the amount of soil and should not be varied. They set up their experiments to reflect their differing points of view. However, this year one student really surprised me with his experiment.
He wanted to grow the plants in the control conditions with just one change. He wanted to open up the barriers of the quad so that plants could share space. He explained, “I want to keep everything the same as the control plants except that the roots can go from one cell to another.
It was a fascinating idea and very doable. He quickly set up his quad and the experiment began. A few weeks into the experiment the student looked disappointed. He said that he expected the plants to fight with each other and for some of the plants to die. Instead the plants were thriving. In fact they were growing better than I had ever seen fast plants grow before. By the end of the experiment he had the most impressive statistics of all the plants. He asked, “I wonder if these plants should be the control plants for the next time around because they are growing so well.” Somehow by sharing the soil space the plants had more efficiently used water and fertilizer and produced the most seeds. When I mentioned this experiment to the biologist at the Barnard greenhouse she said that plants sharing space is actually a cutting edge research field in botany. Sometimes the most important part of teaching is putting faith in your students and letting them take more ownership over their learning. They will surprise and impress you with what they can do. Also you might learn something new from your students.
