Graphs

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Graphs!
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What Is a Graph?

• Graphs are easy-to-read drawings or pictures that
  provide a great deal of information in a small
  amount of space.
• Graphs are constructed from data.
• Data is information. Pure and simple.
• Examples of data
• The number of kilometers from New York to Los
  Angeles.
• The number of centimeters of rain that fell this
  summer.
• Your height.

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Data

• As scientists, youll need to be able to record
  information, evaluate experiments, and draw
  conclusions.
• To do all of this, you need to know how to use
  data tables and draw graphs.

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Data Tables

• To organize data we use a data table.
• A properly constructed data table follows these
  guidelines
• A descriptive title
• Variables describing what information has been
  collected
• Units telling how those variables were measured
• Data collected in ordered pairs
• All work done neatly

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Example of a Data Table

• Heating of Compound X

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Reading a Graph

• A graph is an exact picture of information in a
  data table. That means that everything thats in
  the data table has to be in the graph -
  EVERYTHING!

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Different Types of Graphs
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Components

• Graphs may include several or all of the
  following components
• Source - The source tells where the information
  shown on a graph was found.
• Title - The title is the main idea of the graph
  or table. It explains what the graph shows.
• Horizontal Axis (x axis) - The horizontal axis is
  the line that runs from left to right on a graph.
• Vertical Axis (y axis) - The vertical axis is the
  line that runs from top to bottom on a graph.
• Key - The key indicates the meanings of the
  symbols used in a graph.

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Source Survey of 7 Girls 7 BoysTitle Ways
Boys and Girls Travel to School
vertical axis
key
Number of Students
horizontal axis
Methods of Travel
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How to Draw a Correct Graph

• Use graph paper or computer
• The title of the x-axis is the independent
  variable, what you manipulate, test or change
  (Remember mix)
• The title of the y-axis is the dependent variable
  what you measure or your data collected
  (Remember dry)
• Numbers go on the lines (not between them)
• Numbers count in a pattern
• Give an informative title
• Graph is an appropriate size and neat.
• Add a key to name each color coded line, bar, or
  sections

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Bar Graph

• A bar graph is used to compare information.

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Bar Graph Questions

• What is the title of the graph?
• What sources would you use to gather the
  information to create this graph?
• What information is listed on the X Y axis?
• What can be answered using this graph?

Writing Utensils in My Desk
Number of Items
Writing Utensils
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Line Graph

• A line graph is used to show change over a period
  of time.

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Line Graph Questions
New Students at CRMS in 2006

• What is the title of the graph?
• What source would you use to gather information
  to create this graph?
• What information is listed on the X Y axis?
• What change does the graph show?
• What can be answered using this graph?

Number of New Students
Month
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Circle or Pie Graph

• A circle or pie graph is used to compare parts or
  segments to the whole.

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Pie Graph Questions

• What is the title of the graph?
• What sources would you use to gather information
  to create this graph?
• How is the key helpful for this type of graph?
• What information can be compared using this
  graph?
• What can be answered using this graph?

How I Spent My Allowance