This document discusses how scientists analyze and represent data. It explains that scientists organize data in tables with independent and dependent variables. They construct graphs like scatter plots and bar graphs to identify patterns and trends in the data. Linear and nonlinear relationships can be represented, with linear graphs showing a constant rate of change. Scientists select models that closely resemble the system being studied and can explain it with few limitations.

1. Unit 1 Lesson 4 Representing Data
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2. Unit 1 Lesson 4 Representing Data
Florida Benchmarks
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• SC.8.N.1.5 Analyze the methods used to develop
a scientific explanation as seen in different fields
of science such as biology, geology, and physics.
• SC.8.N.1.6 Understand that scientific
investigations involve the collection of relevant
empirical evidence, the use of logical reasoning,
and the application of imagination in devising
hypotheses, predictions, explanations and models
to make sense of the collected evidence.

3. Unit 1 Lesson 4 Representing Data
Florida Benchmarks
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• SC.8.N.3.1 Select models useful in relating the
results of their own investigations.
• MA.6.A.3.6 Construct and analyze tables, graphs,
and equations to describe linear functions and
other simple relations using both common
language and algebraic notation.

4. Unit 1 Lesson 4 Representing Data
Florida Benchmarks
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• LA.8.4.2.2 The student will record information
(e.g., observations, notes, lists, charts, legends)
related to a topic, including visual aids to organize
and record information, as appropriate, and
attribute sources of information.

5. Modeling Data with Graphs
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How do scientists make sense of data?
• All of the different types of scientific investigations
involve the collection of data.
• Data are the facts, figures, and other evidence
scientists gather when they conduct an
investigation.
• Scientists organize and record their data in data
tables.
Unit 1 Lesson 4 Representing Data

6. How do scientists make sense of data?
• Data tables often have two columns.
• One column lists the independent variable,
which is the variable that is deliberately
manipulated in an investigation.
• The other column lists the dependent variable,
which is the variable that changes as a result of
manipulation of the independent variable.
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Unit 1 Lesson 4 Representing Data

7. How do scientists make sense of data?
• Scientists often analyze data for patterns or
trends by constructing graphs of the data.
• The type of graph they construct depends upon
the data they collected and what they want to
show.
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Unit 1 Lesson 4 Representing Data

8. How do scientists make sense of data?
• A scatter plot is a graph with points plotted to
show a possible relationship between two sets of
data.
• In a scatter plot, the horizontal x-axis usually
represents the independent variable.
• The vertical y-axis usually represents the
dependent variable.
• To show the general relationship between the two
variables, a “line of best fit” may be used.
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Unit 1 Lesson 4 Representing Data

9. More Graphing!
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What do graphs show?
• Scientists use different types of graphs to show
different types of information about data.
• A bar graph is used to display and compare data
in a number of separate categories.
• A circle graph is used to show how each group of
data relates to all of the data.
Unit 1 Lesson 4 Representing Data

10. Throw Me a Curve!
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What kinds of patterns can be shown
using 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.
• Graphs make it easy to tell if something is
increasing, decreasing, or staying the same.
Unit 1 Lesson 4 Representing Data

11. What kinds of patterns can be shown
using graphs?
• In some cases, a line can be used to show the
trend of data on a graph.
• If the relationship between the independent and
dependent variables can be shown with a straight
line, the graph is called a linear graph.
• A straight line shows that the rate of change of
the dependent variable with respect to the
independent variable is constant.
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Unit 1 Lesson 4 Representing Data

12. What kinds of patterns can be shown
using graphs?
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Unit 1 Lesson 4 Representing Data
• The density of water as a function of temperature
is a linear relationship.

13. What kinds of patterns can be shown
using graphs?
• A graph in which the relationship between the
variables cannot be shown with a straight line is
called a nonlinear graph.
• If the product of variables remains constant, the
variables are said to have an inverse relationship.
• A graph of an inverse relationship is a smooth
curve that becomes nearly vertical and horizontal
at opposite ends.
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Unit 1 Lesson 4 Representing Data

14. What kinds of patterns can be shown
using graphs?
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Unit 1 Lesson 4 Representing Data
• The relationship between volume and pressure for
a gas at a constant temperature is a nonlinear
relationship.

15. The Perfect Model
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How do scientists select models?
• Scientists use many different kinds of models.
• Some are physical models, such as maps and
globes.
• Others are mathematical models, including
equations and simulations of movement.
Unit 1 Lesson 4 Representing Data

16. How do scientists select models?
• A model is a representation of an object or a
process that allows scientists to study something
in greater detail.
• A model that is too simple or too complicated may
not be useful.
• The best models are those that most closely
resemble the system, process, or other entity they
represent.
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Unit 1 Lesson 4 Representing Data

17. How do scientists select models?
• Scientists select models based on how much the
models can explain.
• In addition, scientists select models based on how
few limitations they have.
• Today, many phenomena in science can be
modeled with great sophistication.
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Unit 1 Lesson 4 Representing Data