This post was written by Trey Smith, the Library of Congress 2015-16 Science Teacher in Residence.
Scientific investigations with plants are a staple in elementary school classrooms. Young learners study plant structures and functions, what plants need to grow, how plants reproduce and pass on genetic information, and how matter and energy move in ecosystems. As they learn core scientific ideas, students should simultaneously engage in the practices of scientists. Historic photographs can serve as windows into planning and carrying out scientific investigations.
Introduce a unit on plants and conducting scientific investigations using three photographs from the Tuskegee Institute (now Tuskegee University) from 1942. The photographs show one Tuskegee student, a second student, and both students in a greenhouse.
When I shared these photographs with fourth graders who were about to study plants, I modified the Library’s Primary Source Analysis Tool to include the sentence stems “I see,” “I think,” and “I wonder” to support the young learners in organizing their analyses.
I modeled recording observations, reflections, and questions on a chart, and then students recorded their thinking on graphic organizers. Students were especially interested in the contents of the bottles and dropper and in what the two scientists were doing. They wondered:
- Why are there multiple bottles?
- What is the purpose of the funnel, since we typically wouldn’t use one to water plants?
Students also wondered about the way the plants were arranged. In each photo, a grid-like system of wires or strings separates the plants. Why might such a grid be useful in scientific study?
The photographs were only one portal into thinking about planning and carrying out scientific investigations.
After analyzing the photographs, we read a picture book about George Washington Carver, who taught at Tuskegee until his death in 1943 and was known throughout the world for his work with plants. Learning about Carver provided ideas about research that can be done with plants, investigation methods, and reasons why we should care about plants.
Before analyzing the photographs, we introduced students to thinking processes of observing, reflecting, and questioning with two potted plants. One plant had been in my freezer for a week. Students described the differences in color between the plants and the way one stood up straighter than the other. They inferred that one was dying, or might be older than the other, and asked questions.
Students practiced important thinking habits by studying historic photographs and looking closely at two plant specimens. Reading about George Washington Carver and studying the photographs helped them identify attributes of planning and carrying out scientific investigations. With that foundation, they could begin planning and carrying out their own investigations with continued support from a teacher.
What do you imagine students might do next in their investigations with plants?