Methods of Science - Doral Academy Preparatory School

Methods of Science

Nature of Science

LESSON 1

Understanding Science

What is science?

Did you ever hear a bird sing and then look in nearby trees to find the singing bird? Have you ever noticed how the Moon changes from a thin crescent to a full moon each month? When you do these things, you are doing science. Science is the investigation and exploration of natural events and of the new information that results from those investigations.

For thousands of years, men and women of all countries and cultures have studied the natural world and recorded their observations. They have shared their knowledge and findings and have created a vast amount of scientific information. Scientific knowledge has been the result of a great deal of debate and confirmation within the science community.

People use science in their everyday lives and careers. For example, firefighters wear clothing that has been developed and tested to withstand extreme temperatures and not catch fire. Parents use science when they set up an aquarium for their children's pet fish. Athletes use science when they use high-performance gear or wear highperformance clothing.

Without thinking about it, you use science or the results of science in almost everything you do. Most likely, your clothing, food, hair products, electronic devices, athletic equipment, and almost everything else you use are all results of science.

Branches of Science

There are many different parts of the natural world. Because there is so much to study, a scientist often focuses his or her work in one branch of science or on one topic within that branch of science. There are three main branches of science--Earth science, life science, and physical science.

Key Concepts

? What is scientific inquiry? ? How do scientific laws and

scientific theories differ? ? What is the difference

between a fact and an opinion?

3TUDY#OACH

Identify the Main Ideas As you read, write one sentence to summarize the main idea in each paragraph. Write the main ideas on a sheet of paper or in your notebook to study later.

Reading Check 1. Name the three main branches of science.

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Reading Essentials

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Key Concept Check 2. Define What is scientific inquiry?

Visual Check 3. State What are four possible ways to test a hypothesis?

Earth Science The study of Earth, including rocks, soils, oceans, the atmosphere, and surface features, is Earth science. Earth scientists might ask questions such as, How do different shorelines react to tsunamis? Why do planets orbit the Sun? What is the rate of climate change?

Life Science The study of living things is life science, or biology. Biologists ask questions such as, Why do some trees lose their leaves in winter? How do birds know which direction they are going? How do mammals control their body temperature?

Physical Science The study of matter and energy is physical science. It includes both physics and chemistry. Physicists and chemists ask questions such as, What chemical reactions must take place to launch a spaceship into space? Is it possible to travel faster than the speed of light? What makes up matter?

Scientific Inquiry

When scientists conduct scientific investigations, they use scientific inquiry. Scientific inquiry is a process that uses a set of skills to answer questions or to test ideas about the natural world. There are many kinds of scientific investigations and many ways to conduct them. The series of steps used in each investigation often varies. The flowchart in the figure below and on the next page shows an example of the skills used in scientific inquiry.

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Steps in Scientific Inquiry

Repeat several times to confirm

Observe and

Question

? State a Problem ? Gather Information ? Infer

Hypothesize and

Predict

Test Hypothesis

? Design an Experiment ? Make a Model ? Gather and Evaluate Evidence or Research ? Collect Data/Record Observations

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Modify/Revise Hypothesis

Reading Essentials

Ask Questions

One way to begin a scientific inquiry is to observe the natural world and ask questions. Observation is the act of using one or more of your senses to gather information and taking note of what occurs. Suppose you observe that the banks of a river have eroded more this year than last year. You want to know why. You note that there was an increase in rainfall this year. After these observations, you make an inference based on these observations. An inference is a logical explanation of an observation that is drawn from prior knowledge or experience. You infer that the increase in rainfall caused the increase in erosion. You decide to investigate further. You develop a hypothesis and a method to test it.

Hypothesize and Predict

A hypothesis is a possible explanation for an observation that can be tested by scientific investigations. A hypothesis states an observation and provides an explanation. You might make the following hypothesis: More of the riverbank eroded this year because the amount, the speed, and the force of the river water increased.

Scientists often use a hypothesis to make predictions. A prediction is a statement of what will happen next in a sequence of events. Scientists make predictions based on what information they think they will find when testing their hypothesis. A prediction for the hypothesis above might be: If rainfall increases, then the amount, the speed, and the force of river water will increase. If the amount, the speed, and the force of river water increase, then there will be more erosion.

Steps in Scientific Inquiry

Hypothesis supported

Reading Check 4. Select Which of the following is a way to begin a scientific inquiry? (Circle the correct answer.) a. observe the natural

world

b. ask questions c. both a and b above

Reading Check 5. Identify What do scientists often use to make a prediction?

Analyze Results

? Graph Results ? Classify Information ? Make Calculations ? Other Processes

Draw Conclusions ? Infer ? Summarize

Communicate Results

? Write Science Journal Articles ? Speak at Science Conferences ? Exchange Information on Internet ? Other Ways of Exchanging Information

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Reading Essentials

Hypothesis not supported

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Reading Check 6. Apply When should you modify your hypothesis?

Make a six-tab book to organize your notes about a scientific inquiry.

Questions Hypothesize and Predict HypToetshtesis Analyze Results CCoomRnDmcerlsuauunwsltiicosantse

Reading Check 7. Describe What is the next step if a scientist's hypothesis is supported?

NOS 4 Methods of Science

Test Hypothesis

When you test a hypothesis, you often test whether your predictions are true. If your prediction is confirmed, then it supports your hypothesis. If your prediction is not confirmed, you might need to modify your hypothesis and retest it.

There are several ways to test a hypothesis when performing a scientific investigation. You might design an experiment, make a model, gather and evaluate evidence or research, or collect data and record your observations. For example, you might make a model of a riverbank in which you change the speed and the amount of water and record observations and results.

Analyze Results

After testing your hypothesis, you analyze your results using different methods. Often, it is hard to see trends or relationships in data while collecting it. Data should be sorted, graphed, or classified in some way. After analyzing the data, additional inferences can be made.

Draw Conclusions

Once you find the relationships among data and make several inferences, you can draw conclusions. A conclusion is a summary of the information gained from testing a hypothesis. Scientists study the available information and draw conclusions based on that information.

Communicate Results

An important part of the scientific inquiry process is communicating results. Ways to communicate results include writing science journal articles, speaking at science conferences, and exchanging information on the Internet. Scientists might share their information in other ways, too.

Scientists communicate results of investigations to inform other scientists about their research and the conclusions of their research. Scientists might apply each other's conclusions to their own work to help support their hypotheses.

Further Scientific Inquiry

Scientific inquiry is not completed once one scientific investigation is completed. If predictions are correct and the hypothesis is supported, scientists will retest the predictions several times to make sure the conclusions are the same each time. If the hypothesis is not supported, any new information gained can be used to revise the hypothesis. Hypotheses can be revised and tested many times.

Reading Essentials

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Results of Science

The results and conclusions from an investigation can lead to many outcomes, such as the answers to a question, more information on a specific topic, or support for a hypothesis. Other outcomes are described in the following paragraphs.

Technology A technical solution can be the answer to a scientific question, such as, "How can the hearing impaired hear better?" After investigation, experimentation, and research, the conclusion might be the development of a new technology. Technology is the practical use of scientific knowledge, especially for industrial or commercial use. Technology, such as a cochlear implant, can help some deaf people hear.

New Materials Space travel has unique challenges. Astronauts must carry oxygen to breathe. They also must be protected against temperature and pressure extremes, as well as small, high-speed flying objects. A spacesuit consists of 14 layers of material. The outer layer is made of a blend of three materials. One material is waterproof. Another protects against high-speed flying objects. The third material is heat and fire-resistant.

Possible Explanations Scientists often perform investigations to find explanations as to why or how something happens, such as, "How do stars form?" For example, to help answer this question, NASA's Spitzer Space Telescope took photos showing a cloud of gas and dust with newly formed stars.

Scientific Theory and Scientific Law

Another outcome of science is the development of scientific theories and laws. Recall that a hypothesis is a possible explanation about an observation that can be tested by scientific investigations.

What happens when a hypothesis or a group of hypotheses has been tested many times and has been supported by the repeated scientific investigations? The hypothesis can become a scientific theory.

Reading Check 8. Define What is technology?

Reading Check 9. Express What are some results of science?

Reading Check 10. Explain How can a hypothesis become a scientific theory?

Copyright ? Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Reading Essentials

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