GRAPHING BASICS

1
GRAPHING BASICS

• Data Management
• Graphing

2
Data Management

• When performing an experiment, you will always
  collect data
• REVIEW
• Quantitative data Data gathered by making
  observations using your senses and includes
  numbers
• Qualitative data Data gathered by making
  observations using your senses and does NOT
  include numbers
• Regardless of the type of data that you collect,
  it should be properly organized in a data table.

3
Data Table Format

• The proper format for a data table is
• Place your independent variable and unit in the
  left-most column
• Place your dependent variable and unit in the
  right-most column
• REVIEW
• Independent Variable
• The thing that is changed by the experimenter
• Dependent Variable
• The thing that is measured in the experiment

DEPENDENT VARIABLE Label (unit)
INDEPENDENT VARIABLE Label (unit)
Data
4
Practice Scenario

• For the following scenario, pull out the parts
  indicated
• Laura was watching a special on HGTV (Home and
  Garden TV) that was on the effects of different
  amounts of fertilizer on plant growth. It said
  that the more fertilizer that could be added, the
  more the plants would grow. She decided to
  experiment to see if it was true. She went to
  her garden and removed 6 tulip bulbs. She placed
  them in 6 identical pots, watered them with the
  same amount of water. She decided to add the
  following amounts of fertilizer to the plants
  Plant A (0g) Plant B (3g) Plant C (6g) Plant D
  (9g). She went back after 10 days and measured
  the height of each plant. She measured the
  plants as follows Plant A (5cm), Plant B (7cm),
  Plant C (9cm), Plant D (11cm).
• What is the hypothesis?
• What is the Control?
• What are the Constants?
• What is the Independent Variable?
• What is the Dependent Variable?

If I add more fertilizer, then the plants will
grow more.
Plant A
Pots, tulips, water, measured after same amt. of
time
Amount of fertilizer
Plant growth
5
Practice Scenario (continued)

• Now, using your answers from the previous slide,
  correctly fill in the data table below. Consult
  the scenario to find the proper numbers to put in
  the table as well.

Dependent Variable
Independent Variable
Amount of Fertilizer (grams)
Plant growth (cm)
0
5
3
7
9
6
9
11
6
Types of Graphs

• After collecting your data, you will need to
  organize it into a graph.
• There are three types of graphs
• Pie/Circle Graph
• Bar Graph
• Line Graph

7
Why Graph?

• Graphs are an effective way to visually display
  the information or data collected in an
  experiment.
• Graphs can clearly illustrate a trend in
  information or data collected. This is one way
  that data can be analyzed.
• It is important to use the correct type of graph
  for the type of information or data presented.

8
Pie/Circle Graph

• These graphs are usually used when data is
  comparing parts to a whole (percentage) or when a
  quantity is broken down
• Example
• How the Miltons family budget is broken down in
  a month

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Bar Graph

• Most often used when comparing groups (words) and
  numbers or numbers that cannot be ordered
• Example
• Comparing the resistance of current passing
  through different types of metal

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Line Graph

• Most often used to show changes over time or
  rates of change in something. It is used when you
  can make a sequential scale with the data being
  collected.
• Example
• Change in average speed compared to the distance
  traveled.

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Titling a Graph

• A title for a graph should describe what the
  experiment was comparing
• For pie graphs
• Titles should name the quantity or thing being
  divided
• Student Hair Color
• For line and bar graphs
• Titles should list the
  dependent variable vs. the
  independent variable
• Temperature vs. Time
• All titles are placed at the TOP of the graph

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Bar Line Graphs

• Bar and line graphs are constructed on a set of
  axes
• X axis runs horizontal
• ( ?)
• Y axis runs vertical
• (?)
• These axes must be labeled properly
• The x-axis should be labeled with the independent
  variable and unit
• The y-axis should be labeled with the dependent
  variable and unit

Dependent Variable vs. Independent Variable
DEPENDENT VARIABLE Label (unit)
INDEPENDENT VARIABLE Label (unit)
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Practice Scenario (continued)

• Now, using your answers from the earlier
  scenario, correctly title and label the axes
  below

Plant Growth Depend on Amount of Fertilizer
Plant Growth (cm)
Amount of Fertilizer (grams)
14
Line Graph