Part 1: Plant A Experiment
Step 1 – Students’ prior knowledge assessed:
First, fourth-graders were asked, “How much sunlight do plants need to grow well?” They selected one of the following options:
- Most plants need only a little sunlight to grow well.
- The more sunlight plants get, the better they grow.
- Sunlight does not affect how most grow.
- Different kinds of plants need different amounts of sunlight to grow well.
Results showed that over one-half (59 percent) of all fourth-graders displayed “complex” prior knowledge, selecting the response “different plants need different amounts of sunlight to grow well.” Approximately 31 percent of fourth-graders displayed “simple” prior knowledge by indicating that all plants need more sunlight to grow best. Ten percent of the fourth-graders provided responses that were rated “incorrect.”
Try It Yourself: Users can go through the animated tutorial presented to students.
Step 2 – Students perform first sunlight investigation:
Students were next asked to use six trays of Plant A to determine where in a greenhouse the plants would grow best. They were presented with an image of a greenhouse with three shelves, labeled from top to bottom with the respective designations “lots of sunlight,” “some sunlight,” and “a little sunlight.” Also shown were images of six trays containing plants, which students were directed to drag onto the shelves of the greenhouse. The students were then directed to click on the “Do Experiment” button on the screen; the plant images on each shelf grew in height and sprouted leaves and flowers. When this action was completed, students were directed to click on the “View Data Table” button and were presented with a completed data table.
Results showed that 80 percent of the students were able to use the simulation to collect appropriate data. Students’ investigations were rated as either correct or incorrect; a correct investigation moved at least one tray to each level of the greenhouse.
Almost one-half (49 percent) of all fourth-graders who displayed “complex” prior knowledge were able to perform the experiment correctly. Approximately 23 percent of fourth-graders who displayed “simple” prior knowledge and 8 percent of those whose prior knowledge was rated “incorrect” were able to perform the experiment correctly.
Try It Yourself: Users can perform the experiment using the animation presented onscreen.
Step 3 – Students draw conclusions:
After the students moved the plant trays into place, conducted the experiment, and viewed their data table, they answered the following questions about their conclusions for Plant A:
Based on your experiments and the results in the data table, how much sunlight does Plant A need to grow best? You may look at your data table again to help you with your answer.
- Lots of sunlight
- Some sunlight
- A little sunlight
Support your answer with specific observations and results from the data table. Type your answer in the box.
Results showed that 93% of fourth-graders could identify that Plant A was a sun-loving plant, and 36% could explain the correct conclusion using evidence from their investigation. Complete explanations explained that Plant A had more flowers and/or leaves on it when it was placed in the part of the greenhouse with the most sunlight.
Approximately 23 percent of all fourth-graders who displayed “complex” prior knowledge and did the experiment correctly were able to give complete explanations. Eight percent of fourth-graders who displayed “simple” prior knowledge and did the experiment correctly were able to give complete explanations. Two percent of fourth-graders whose prior knowledge was rated “incorrect” and did the experiment correctly were able to give complete explanations.
Try It Yourself: Users can perform the experiment, view the data table, and then draw conclusions using the animation presented onscreen.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2009 Science Assessment.