Section 3: Methods of Science Biologists use specific methods when conducting research. K What I Know W What I Want to Find Out L What I Learned

Essential Questions What are the differences between an observation and an inference? What are the differences among a control, independent variable, and dependent variable? What are the scientific methods a biologist uses for research? Why are the metric system and SI important? Copyright © McGraw-Hill Education Methods of Science

Vocabulary Review New continued New theory constant data metric system observation inference scientific method experiment control group experimental group independent variable dependent variable New continued constant data metric system SI Methods of Science Copyright © McGraw-Hill Education

Ask a Question Scientific inquiry begins with observation. Scientific inquiry involves asking questions and processing information from a variety of reliable sources. Methods of Science Copyright © McGraw-Hill Education

Ask a Question Scientific Methods Scientific inquiry begins with observation, a direct method of gathering information in an orderly way. The process of combining what you know with what you have learned to draw logical conclusions is called inferring; the conclusions themselves are called inferences. The methods scientists use to gather data and answer questions are referred to as scientific methods. Methods of Science Copyright © McGraw-Hill Education

Visualizing Scientific Methods Animation FPO Add link to concepts in motion animation (Figure 14) from page 17 here. Methods of Science Copyright © McGraw-Hill Education

Add link to BrainPOP from page 18 here. Scientific Methods BrainPOP FPO Add link to BrainPOP from page 18 here. Methods of Science Copyright © McGraw-Hill Education

Form a Hypothesis A hypothesis is a testable explanation of a situation. When a hypothesis is supported by data from multiple investigations, the hypothesis is usually considered valid and is accepted by the scientific community. If the hypothesis is not supported by scientific investigations, the hypothesis is revised, and additional investigations are conducted . Methods of Science Copyright © McGraw-Hill Education

Collect the Data Controlled experiments When a scientist conducts an experiment, they investigate a phenomenon in a controlled setting to test a hypothesis. The control group in an experiment is the group used for comparison. An experimental group is a group exposed to the factor being tested. Methods of Science Copyright © McGraw-Hill Education

Collect the Data Experimental design During a controlled experiment, only one factor can change at a time. Independent variable—the tested factor that might affect the outcome of the experiment Dependent variable—results from or depends on changes to the independent variable. Constant—a factor that remains fixed during an experiment while the independent and dependent variables change. Methods of Science Copyright © McGraw-Hill Education

Add link to Virtual Lab from page 18 here. Dependent and Independent Variables Virtual Lab FPO Add link to Virtual Lab from page 18 here. Methods of Science Copyright © McGraw-Hill Education

Collect the Data Data gathering As scientists test their hypotheses, they gather data– information gained from observations. Quantitative data can be collected as numbers, such as measurements of time, temperature, length, mass, etc. Qualitative data are descriptions of what our senses detect. Data is organized in notebooks and tables Methods of Science Copyright © McGraw-Hill Education

Collect the Data Investigations Metric system Not all scientific inquiry is based on controlled experiments Investigations rely on observation and collection of data rather than manipulating variables Metric system The metric system uses units with divisions that are powers of ten. SI units (International System of Units) are commonly used in science for consistency and ease of communication. Copyright © McGraw-Hill Education Methods of Science

Analyze the Data After data collection, scientists use analyses to ask questions, such as “Has my hypothesis been supported?” or, “Are more data needed?” Patterns in data can be displayed in tables and graphs. Data analysis determines if the hypothesis is supported or rejected. Methods of Science Copyright © McGraw-Hill Education

Report Conclusions Before a scientist can publish their findings, it must be peer-reviewed. If the reviewers agree on the merit of a paper, it is published in a scientific journal. Other scientists use published papers to evaluate and develop their own research. Methods of Science Copyright © McGraw-Hill Education

Student Scientific Inquiry As a biology student, you will have the opportunity to participate and design your own investigations Lab safety practices are designed to keep you, your classmates, and your teacher from harm during experiments. Lab safety sheets will inform you of any hazards present in an activity. Methods of Science Copyright © McGraw-Hill Education

Review Essential Questions Vocabulary What are the differences between an observation and an inference? What are the differences among a control, independent variable, and dependent variable? What are the scientific methods a biologist uses for research? Why are the metric system and SI important? Vocabulary observation inference scientific method experiment control group experimental group independent variable dependent variable constant data metric system SI Copyright © McGraw-Hill Education Methods of Science