So, you've sparked students' curiosity and questions about plants. Now, how do you guide and support them to think and act like scientists as they design and conduct growing investigations? While the "scientific method" is a familiar framework for science investigations, science educators increasingly emphasize that the nature of science and science inquiry is much richer, broader, and more flexible than the traditional lock-step method.
"Scientific inquiry is far more flexible than the rigid sequence of steps commonly depicted as The Scientific Method ... it is more than just doing experiments, and it is not confined to laboratories ... more imagination and inventiveness are involved in scientific inquiry than many people realize.... Unexpected observations often result in new questions for scientific study." -- Project 2061 Benchmarks
The National Science Education Standards underscore that the main strategy for teaching science should be inquiry into meaningful, relevant questions generated from student experiences. The structure of individual investigations, of course, will vary depending on the types of questions your students are exploring (e.g., "What's inside a bean seed?" vs. "Which lights are better for plant growth?"), their developmental levels, and your classroom resources and priorities. Some questions might warrant observing and describing plants and phenomena, while others might require collecting, organizing, and classifying specimens. As students develop comfort with a range of science skills, their investigations will more frequently include "fair tests."
Growing Through Trial and Error
"When my sixth graders set up controlled experiments with FastPlants," reports LaCrescent, MN, teacher Scott Tyink, "many of their results were inconclusive and some were conflicting with what we'd learned earlier or believed to be true. When this happens, we always ask what else we could try or how we might modify our investigation. "I've also found that students often choose to look at only one factor -- plant height, for instance -- but later they begin to notice other factors like the leaf color, shape, or flowers. It can be a challenge to persevere and sift through data. Sometimes students realized in the midst of experiments that they hadn't collected enough data or collected it well enough to make sense of it. This really helped them understand the need to plan and sometimes revise investigations."
Even when investigations are in the form of controlled experiments, science inquiry is not nearly as sequential and tidy as suggested by what we've come to know as the scientific method. How do you set a tone in the classroom that encourages risk taking and flexible thinking? How do you help students recognize that it's okay to not know answers, or to come up with results that conflict with their own hypotheses? And how do you support them to see themselves as problem solvers who have the tools and habits of mind to systematically investigate and continue to explore and ask new questions?
Donna Kemp's junior high students in Sparta, WI, have compared different different brands of grow lights. They measured only the smallest and tallest bean plant under each of three light conditions. Then one student questioned whether this system was the fairest way to take measurements. "Someone suggested taking an average of the plant heights under each condition," reports Donna. They also discovered that plants under the full-spectrum tubes were actually shorter than the others, she adds, and some kids were afraid that the experiment wasn't working. Upon further observation, they noticed that there were other characteristics such as leaf size and color that also differed under different light conditions. "Students realized that although they'd only been looking at height, there were other important factors to observe," she notes. "Though shorter, those under the full-spectrum lights seemed to have more, larger, and healthier looking leaves." Students decided to revise and restart the investigation, this time comparing the number, size, and color of leaves.
Thinking and Acting Like Scientists
Here are some key aspects and values of the nature of science to consider as you guide student investigations, and suggestions for routinely structuring experiences that help students think and act like scientists.
Scientists use their own and others' knowledge and experiences as starting points for investigations. Help students identify their own conceptions -- what they believe and what they already know about the topic being explored. Suggest relevant resources students can use to further inform their investigations. Then help them use this information and their own experiences and observations as springboards for formulating testable questions, hypotheses, and so on.
Scientists have to be careful observers. Routinely asking questions like What did you observe that lead you conclude that ...? What do you notice about...? How is it different than ...? can help students become keener observers and to distinguish between what they actually observe (evidence) and what they infer. Consider having students practice and hone their observation skills through activities such as "Flowers Up Close" or "Plant Private Eyes" from GrowLab: Activities for Growing Minds.
Scientists are collaborative. Scientists share their ideas, research designs, and conclusions with others, and work together to refine them. Give your students opportunities to enhance their own learning by working in small groups to observe and explore, then design, and finally conduct investigations. Provide opportunities for students to reflect on how contributions of group members enriched the process. Routinely encourage groups to share, review, question, and comment on one another's investigation plans and results.
Scientists systematically investigate their questions. When planning investigations, help students consider the "steps" they'll take in terms that help them think through the problem, rather than simply memorize a formula. Some of the questions to consider throughout the process are: What do we want to find out about? How can we make the best observations? What do we already think we know or have we observed about...? What is the best way to answer our questions? What types of data will we need? How can we make it a "fair" test? What types of observations or measurements should we take? How can we organize and communicate the data and results to present the clearest answer or strongest explanation?
Scientists communicate in a variety of ways. Carefully and accurately communicating details of investigations and results is critical to being a good scientist. Students should have opportunities to communicate in a range of ways -- via journals, reporting out, graphing, charting, discussing and debating with peers, and so on.
Legitimate skepticism and respect for evidence are important to science inquiry. They are also important habits of mind that enable all of us to and are told! This includes examining and questioning experimental designs and evidence, and judging the strength of data and information used. It involves asking questions such as: What other factors may have influenced our results? Would we get the same results if we were to repeat this? Does the evidence support the conclusions? Provide opportunities for routine self- and peer-review as students design and communicate results of investigations. Consider staging a culminating "science conference" as a forum for students to share investigations and results and have them critically reviewed by others.
Science is dynamic and tentative. Good scientists recognize that scientific "knowledge" is not fixed, and theories are revised or discarded as new information is revealed. Provide opportunities for students to revisit their earlier ideas and theories and identify how their ideas have changed based on their observations and investigations.
Science involves a lot of trial and error. Try to cultivate an atmosphere that accepts conflicting results or experiments that seem like "failures" as exciting opportunities to learn. Help students recognize that being "right" or proving one's hypothesis should not the goal. Some of the most important science discoveries have been accidental!
Science investigations are often long-term. Plan your schedule to allow for ongoing involvement in growing investigations. The initial phase (brainstorming questions, planning and setting up investigations, and so on) may take several class periods, but once started, investigations may require only short periods over several weeks for observing and collecting data.
Science investigations generate new questions. Help students view science inquiry as an ongoing process by routinely tracking new question time for students independently or in groups to pursue questions that result from their growing experiences.