Investigating Hypotheses

High school students use technology to help frame science investigations

Carly Elliot teaches science at a small, rural high school. She uses the community's watershed as a living laboratory for teaching biology, ecology, and other scientific concepts. Students can take Introduction to Science Research as an elective in ninth or 10th grade, then continue with independent research projects in 11th or 12th grade.

The school is increasing its focus on inquiry learning as an instructional strategy. Inquiry learning is new to many students. Elliot has decided to spend more class time focusing on generating and testing hypotheses-a fundamental skill for successful inquiry learning.

Implementing Research-Based Strategies

As students revise and refine their ideas in the course of posing and testing a hypothesis, they are following a process that leads to deeper understanding.

• Researchers have found that inquiry methods help students gain a better understanding of fundamental concepts in science (White & Frederickson, 1997, 1998).

Certain instructional strategies make inquiry learning more successful. At the introductory level, Elliot explains a scientific principle, then asks students to generate a hypothesis based on that principle. Generating good questions that can be answered by research and observation is at the heart of scientific inquiry. Before proceeding with experiments, Elliot spends considerable class time having students explain their hypotheses, both in writing and aloud.

• Understanding increases when students are asked to explain the scientific principles they are working from and the hypotheses they generate from these principles (Lavoie, 1999; Lavoie & Good, 1988; Lawson, 1988).

The National Science Education Standards define science as an active process, involving both ihands-oni and iminds-oni experiences. Elliot immerses her students in the scientific method by getting them involved as data-gatherers for GLOBE, an online resource that engages students in hands-on science education. She uses the protocols and online resources developed by GLOBE to meet several instructional goals, including:

• Use the inquiry method to design and conduct experiments
• Take scientifically valid measurements
• Use technology to record and report accurate data
• Create maps and graphs to analyze data sets
• Collaborate on research with scientists and other students around the world

Technology Supporting Success

Because her community is crisscrossed by rivers, Elliot uses water studies, or hydrology, as an introduction to data gathering. Her science team shares a class set of handhelds and special science probes for collecting data about turbidity, dissolved oxygen, nitrogen, and other measures of water quality. Her team was trained on how to use them in water studies a year ago, and each year their understanding grows. She finds students have very little difficulty learning the technology tools.

She introduces students to the equipment in the school laboratory. They test and compare tap water and a bucket of rainwater, as well as bottled water from a school vending machine. Elliot explains why scientists take multiple samples from the same source to control for experimental error. She tells them the data they gather will be added to datasets used by students and scientists around the world; accuracy is essential.

In the computer lab, Elliot has students use their lab data to generate and analyze graphs, which help students observe patterns and detect anomalies. A student might ask: Why was dissolved nitrogen higher in one sample? Elliot might follow up with another question that reminds the student of the underlying principle: What could make the nitrogen level increase? What do we know about nitrogen? As a class, students select four well-designed hypotheses to test in the field.

Students work in small teams, using handhelds and probes to test the hypotheses. They take turns taking measurements and recording data. Elliot schedules several short field trips to allow students to gather water samples from streams and lakes. She also makes available datasets gathered by students at the same sites in previous years, along with data about rainfall, snowpack, and other factors that can affect water quality.

Students' measurements are more precise when using handhelds. Students accomplish more data collection during field trips. The graphs help them spot patterns and raise better questions to pursue in later investigations.

The second semester, students design their own projects about water quality. Students know they will have the chance to present their projects at the schoolwide science fair in the spring, and motivation is high to design a quality project.

See Exhibiting Effort for a continuation of this example.