Almost any lesson can be modified to better incorporate, reinforce, and make explicit the nature and process of science. To see how, visit Modifying your current lessons and our additional tips and strategies. The lesson below is an example of a modified physical science lesson.

Lesson: Sink or float?

Overview: This is an inquiry-based lesson on buoyancy which can also serve as a foundation for deeper explorations of density. Students begin by observing objects that sink and float, formulate expectations about whether other items will float or sink in water, and perform an experiment to test their expectations. In its original format, this lesson aims to encourage student skills in experimental design, testing simple hypotheses, and grouping objects by shared traits. The modifications suggested below communicate additional aspects of the process of science.

Suggested modifications:

• Clarify terms. Within this lesson, students are asked to predict (hypothesize) which objects they think will float. The terms prediction and hypothesis are used interchangeably here, but in fact, the two concepts are distinct. Hypotheses are proposed explanations based on observations and/or scientific knowledge; they are not mere guesses about what will happen. Hypotheses can be used to generate predictions — ideas about what will happen in a given situation if one’s hypothesis is true. (Note that, for clarity, this website uses the term expectation instead of prediction.) This lesson provides an excellent opportunity for students to pinpoint when they were simply guessing what would float, and when they began to formulate a hypothesis (e.g., objects float because they are less dense than their surrounding medium) that generates testable expectations (e.g., a bunch of bananas will float in a bucket of water).
• Apply the Science Flowchart. In this lesson, students move from initial observations, sharing data, and communicating with others to testing ideas, developing explanations, generating expectations, gathering more data, and interpreting that data in order to develop an explanation for the phenomenon of buoyancy. Have students trace their pathways through the flowchart to emphasize the nonlinearity of their investigation.
• Emphasize that scientists often approach problems in different ways and do not always agree. Point out that not all students will have the same explanations nor will they have carried out their investigations in the same way. Encourage a class discussion that focuses on the validity of multiple approaches to scientific investigations.