Chapter 1 Section 2 Scientific Methods Bellringer Complete
Chapter 1 Section 2 Scientific Methods Bellringer Complete these two tasks: 1. Describe an advertisement that cites research results. 2. Answer this question: Why is it important for scientists to write reports about their findings? Write your answers in your science journal.
Chapter 1 Section 2 Scientific Methods What You Will Learn • Scientists ask questions, make observations, form hypotheses, test hypotheses, analyze results, and draw conclusions. • Scientists communicate their steps and results from investigations in written reports and oral presentations.
Chapter 1 Section 2 Scientific Methods What are Scientific Methods? • Scientific Methods are the ways in which scientists follow steps to answer questions and solve problems. • All life scientists share a curiosity about the natural world and similar methods to investigate it. • Scientists may use the same steps in their investigations, but not always in the same order.
Chapter 1 Section 2 Scientific Methods
Chapter 1 Section 2 Scientific Methods Ask a Question • An observation may be hard to explain or out of the ordinary. • Such an observation can lead to a question. • Looking for answers may lead to more observations and more questions.
Chapter 1 Section 2 Scientific Methods Make Observations • Observations must be made with great care and attention to details. • Observations are only useful if they are accurately made and recorded. • Records of observations include measurements, tables, photographs, and written descriptions.
Chapter 1 Section 2 Scientific Methods Make Observations, continued • Any information gathered through the senses is an observation. • Some typical observations include measurements of length, volume, time, speed, or temperature. • Observations can describe the color, shape, or behavior of an organism.
Chapter 1 Section 2 Scientific Methods Form a Hypothesis • After asking questions and making observations, scientists may form a hypothesis. Sometimes observations lead to several hypotheses. • A hypothesis is a possible explanation or answer to a question. • A hypothesis needs to be testable.
Chapter 1 Section 2 Scientific Methods Form a Hypothesis, continued • After forming a hypothesis, a scientist usually makes a prediction. • The prediction is usually stated in an ifthen format. • The prediction is used to set up an experiment to test the hypothesis.
Chapter 1 Section 2 Scientific Methods Test the Hypothesis • Scientists conduct controlled experiments to test their hypotheses. • A controlled experiment tests only one factor at a time and consists of a control group and one or more experimental groups. • A factor is anything in an experiment that can influence the experiment’s outcome.
Chapter 1 Section 2 Scientific Methods Test the Hypothesis, continued • In a controlled experiment, every factor must be kept the same except for the one factor being tested. • The one factor that is tested, or changed, in an experiment is called the variable.
Chapter 1 Section 2 Scientific Methods Test the Hypothesis, continued • The group of test subjects that includes the variable is called the experimental group. The group that does not change is called the control group. • The only difference between the control group and the experimental group is the variable being tested.
Chapter 1 Section 2 Scientific Methods Test the Hypothesis, continued
Chapter 1 Section 2 Scientific Methods Test the Hypothesis, continued • In addition to carefully controlled factors, a good experiment should test many individuals. • When scientists test many individuals, and repeat the experiment several times, the results are more certain.
Chapter 1 Section 2 Scientific Methods Test the Hypothesis, continued
Chapter 1 Section 2 Scientific Methods Analyze the Results • After scientists finish their tests, they must analyze the results. • Data are often organized into graphs or tables. • This helps scientists focus on the effects of the variable being tested.
Chapter 1 Section 2 Scientific Methods Draw Conclusions • After scientists analyze the results, they can draw conclusions about whether the results support their hypotheses. • When the results do not support the original hypothesis, scientists still learn from the experiment. • A single experiment rarely answers a complex question. Each experiment builds on prior knowledge, and suggests areas of future study.
Chapter 1 Section 2 Scientific Methods Communicate Results • After scientists complete an investigation, they communicate their methods, results, and conclusions. • By communicating with written reports and oral presentations, scientists allow other scientists to repeat their work to see if the results are the same. • Sharing information may also help other scientists with their own investigations. In this way, the scientific methods help strengthen our knowledge.
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