Unit 1 Lesson 2 Scientific Investigations Parts of

Unit 1 Lesson 2 Scientific Investigations Parts of a Whole What are some types of scientific investigations? • Two basic types of scientific investigations are experiments and observations. • Experiments are often based on observations. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations What are some types of scientific investigations? • An experiment is an organized procedure to study something under controlled conditions. • Many experiments are done in a laboratory, where variables are easier to control. • Experiments are also done in the field, where it is easier to show certain processes act in nature. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations What are some types of scientific investigations? • Some scientific investigations involve only observation. Observation is the process of obtaining information by using the senses. • Making a model may be part of a scientific investigation. • Models are useful for studying things that are very small, large, or complex. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations What are some parts of scientific investigations? • Data are information gathered by observation or experimentation that can be used in calculating or reasoning. • Scientists analyze data to understand the relationship between the independent variable and the dependent variable. • Based on their analysis of the data, scientists draw conclusions about the hypothesis. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations Many Methods What are some scientific methods? • Scientific investigations do not always follow exactly the same steps in the same order. • Some of the steps can be repeated. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations What are some scientific methods? • Here are some steps in scientific methods: • Defining a problem • Forming a hypothesis and making predictions • Planning an investigation Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations What are some scientific methods? • Identifying variables • Collecting and organizing data • Interpreting data and analyzing information • Drawing and defending conclusions Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations Make It Work How are scientific methods used? • Scientists determine the best way to test a hypothesis, choosing an experiment, an observation, or a combination of both. • Even when an investigation does not support a hypothesis, the data can help scientists shape future investigations. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations Quality Control What are some characteristics of good scientific investigations? • Certain checks help ensure that good scientific practices are followed. • Experiments must be verified by repetition and replication. • Results must be reviewed by other scientists not involved in the investigation. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations How is repetition different from replication? • Repetition is done when the same scientist repeats the study in the same location. • Replication is done when other scientists reproduce the study in different locations. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 1 Lesson 2 Scientific Investigations How can you evaluate the quality of scientific information? • Peer-reviewed scientific journals are the most reliable. • Books written by scientists about their field of study are trustworthy. • Government or academic web pages are the most reliable Internet sources. • Commercial web pages are often unreliable. Copyright © Houghton Mifflin Harcourt Publishing Company