1. < BackNext >PreviewMain Chapter 2 Data in Science Preview Section 1 Tools and Models in ScienceTools and Models in Science Section 2 Organizing Your DataOrganizing Your Data Section 3 Analyzing Your DataAnalyzing Your Data Concept Map

2. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Bellringer During investigations, scientists need to collect accurate and reproducible data. To achieve this goal, what characteristics are important in a tool that scientists use? Write your answer in your Science Journal.

3. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 What You Will Learn Tools are used to make accurate measurements while collecting data. The International System of Units (SI) is a system of measurements used by most scientists. A model uses familiar things to describe unfamiliar things. Physical, conceptual, and mathematical models are commonly used in science. Models help scientific progress through their use in theories and laws.

4. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Tools in Science A tool is anything that helps you do a task. Scientists use many different tools to help them make observations, take measurements, and analyze data.

5. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Making Measurements The International System of Units (SI) is the standard system of measurement. All SI units are expressed in multiples of 10. Prefixes are used to express SI units that are larger or smaller than basic units. For example, kilo- means 1,000 times, and milli- indicates 1/1,000 times.

6. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Making Measurements, continued Length, mass, volume, density, and temperature are common measurements. The meter is the basic SI unit of length. The kilogram (kg) is the basic SI unit for mass. Mass is the measure of the amount of matter in an object.

7. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Making Measurements, continued Liquid volume is expressed in liters (L). Volume is a measure of the size of an object in three-dimensional space. The volume of solid objects is usually expressed in cubic meters (m 3 ).

8. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Making Measurements, continued Density is the ratio of the mass of a substance to the volume of the substance. The temperature of a substance is a measurement of how hot or cold the substance is. The kelvin (K) is the SI unit for temperature.

9. < BackNext >PreviewMain Data in Science Chapter 2

10. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Models in Science A model is a representation of an object or system. A model uses something familiar to help you understand something that is not familiar. Physical, conceptual, and mathematical models are commonly used in science. Models have limitations because they are never exactly like the real thing.

11. < BackNext >PreviewMain Data in Science Chapter 2 Physical, Mathematical, and Conceptual Models

12. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Using Models for Scientific Progress Models are often used to help illustrate and explain scientific theories. In science, a theory is a system of ideas that explains many related observations and is supported by a large body of evidence acquired through scientific investigation.

13. < BackNext >PreviewMain Section 1 Tools and Models in Science Chapter 2 Using Models for Scientific Progress, continued When a model correctly predicts the results of many different experiments, a scientific law can be constructed. In science, a law is a descriptive statement or equation that reliably predicts events under certain conditions.

14. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 Bellringer A variable is a factor in an experiment that can change. In an experiment to test the safety of a new car model, engineers performed crash tests at different angles of impact and at different speeds. Then, they measured the effect on the car after each impact. What are the variables in this experiment? Write your answer in your Science Journal.

15. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 What You Will Learn Scientists use data tables and graphs to organize information. The independent variable is the factor or parameter that the investigator can change. The dependent variable is the factor or parameter that the investigator measures. Graphs help show patterns in data. Linear and nonlinear graphs show different relationships between the variables.

16. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 Creating a Data Table Scientists create data tables to organize information. Data tables make information easier to interpret and understand. In an experiment, the independent variable is the factor that the investigator changes or deliberately manipulates.

17. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 Creating a Data Table, continued The dependent variable is the factor that the investigator measures. It changes in response to the independent variable. Controlled parameters are factors that stay constant throughout the experiment. Variable parameters are factors that change, or vary, throughout the experiment.

18. < BackNext >PreviewMain Data in Science Chapter 2 Independent and Dependent Variables

19. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 Creating a Graph Graphs help identify trends in data and make predictions. To create a graph, first use a data table to determine the graph’s axes (singular, axis). An axis is a reference line that forms one side of a graph. Next, determine the range and scale of the axes.

20. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 Creating a Graph, continued Then, plot the data points and draw a line of best fit if needed. The line of best fit is a smooth line that is drawn to “fit,” or to include, some but not all of the data points. Finally, give the graph a title that helps people recognize what the graph describes.

21. < BackNext >PreviewMain Data in Science Chapter 2

22. < BackNext >PreviewMain Data in Science Chapter 2

23. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 Patterns Shown by Graphs When you graph data, you can identify what the pattern, or trend, of the data is. A trend shows the relationship between the two variables studied in the experiment. A graph in which the relationship between the independent variable and the dependent variable can be shown with a straight line is called a linear graph.

24. < BackNext >PreviewMain Section 2 Organizing Your Data Chapter 2 Patterns Shown by Graphs, continued Any graph in which the relationship between the variables cannot be shown with a straight line is called a nonlinear graph. Graphs allow scientists to determine if the relationship between the variables is direct or inverse.

25. < BackNext >PreviewMain Data in Science Chapter 2

26. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Bellringer How can you use the slope of a line to analyze data? Write your answer in your Science Journal.

27. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 What You Will Learn Mathematics is an important tool for understanding and summarizing large quantities of information. The accuracy and reproducibility of data affect the results and conclusions of scientific studies. The mean, median, and mode are terms used to describe and analyze an entire set of data. Slope is the degree of slant, or steepness, of a straight line. The slope of a linear graph represents a constant that can be used to help analyze a set of data.

28. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Why Mathematics? Mathematics is an important tool for understanding and summarizing data. Mathematics is often called the language of science because it allows scientists to easily share their findings with each other in a language that everyone understands: numbers!

29. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Accuracy of Data When scientists conduct experiments, they want to collect accurate data. Accuracy has to do with the correctness of a measurement. Accurate measurements are free of errors.

30. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Reproducibility of Data When scientists conduct investigations, they want their results to be able to be repeated, or reproduced, by other scientists. Reproducibility has to do with the ability to reproduce similar data. Data must be reproducible in order for other people to agree with your conclusions.

31. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Describing the Entire Set of Data Mean, median, and mode summarize an entire set of data. The mean, or average, is found by adding all the data points together, then dividing the sum by the total number of data points.

32. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Describing the Entire Set of Data, continued The median is the value of the data point in the middle when the data are placed in order from smallest to largest. The mode is the number that appears most often in a data set.

33. < BackNext >PreviewMain Data in Science Chapter 2

34. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Slope of a Line In math, slope is defined as the degree of slant of a line. The slope of a straight line is found by dividing the rise by the run, often described as “rise over run.”

35. < BackNext >PreviewMain Section 3 Analyzing Your Data Chapter 2 Slope of a Line, continued The slope of a straight line represents a constant that can be used to understand and analyze data. Linear and nonlinear graphs show different relationships in the data.

36. < BackNext >PreviewMain Data in Science Chapter 2

37. < BackNext >PreviewMain Data in Science Chapter 2 Shapes of Graphs and Mathematical Relationships

38. < BackNext >PreviewMain Chapter 2 Data in Science Use the terms below to complete the concept map on the next slide. mathematics theories slope mean graphs models direct linear relationships Concept Map

39. < BackNext >PreviewMain Data in Science Chapter 2 Concept Map

40. < BackNext >PreviewMain Data in Science Chapter 2 Concept Map