Data Management

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Data Management

• Topic 1.1
• Variables Relationships

Outcomes A2 Analyze graphs or charts of
situations to identify specific information C10
Describe real-world relationships depicts by
graphs, tables of values and written descriptions
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Think about it

• Tree farming is an important business in Atlantic
  Canada. Tree farmers want to make sure that each
  year there are enough Christmas trees of the
  right size to sell. When tree farmers try to
  predict the size of trees, they must consider the
  factors that affect growth.
• Questions
• Why is it important to predict the size of trees
  from year to year?
• How are Christmas trees priced?
• How can this help the farmer to predict income?

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Mind Mapping

• Visual graphics that show relationships between
  factors.

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(No Transcript)
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Add the following 4 factors to the mind map
belowWind speedNumber of pests that live in
the treesAmount of space that the trees have in
which to growNumber of people available to tend
the tree farm
Add at least 2 other factors you can think of
that can affect tree growth.
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Which factors can the farmer control?
Factors the farmer can control How the farmer can control them






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Types of Variables

• Independent variable A factor that affects
  another factor in an experiment or a
  relationship.
• Dependent Variable The factor that is affected
  by the other factors in an experiment of a
  relationship. It can be thought of as the result
  or what you measure. This depends on what you
  did to it.
• For example
• How well you do on a test might depend on the
  number of classes you attended, how much you
  participated in the class activities, or how long
  you studied for the test.
• In this example, what you measure (the result) is
  your test score. It is the DEPENDENT VARIABLE.
  What you did to achieve your test score
  (attending class, participating in class
  activities and length of time studying) are the
  INDEPENDENT VARIABLES.

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Control Variables

• In order to know exactly how one particular
  variable will affect another, you must hold all
  other possible variables constant.
• You must make sure that only one variable changes
  during an experiment and everything else is kept
  the same.
• All the other factors that might possibly affect
  the results of your experiment are known as
  CONTROL VARIABLES.
• For example, if you want to know what affect
  light will have on the growth of tomato plants,
  WHAT WOULD YOU DO?

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Control Variables

• What did you suggest?
• Grow many plants (e.g. 10 plants)
• Use 10 identical pots,
• Add exactly the same amount and type of soil to
  each pot,
• Plant the same number and type of seeds in each
  pot,
• Add the same type and amount of fertilizer to
  each pot, and
• Water the pots with the same amount of water.
• The ONLY thing that should be different is the
  amount of light you expose each of the plants to
  during the experiment.
• That way you will know that any difference
  between the plants is caused by the different
  light conditions and not some other variable.

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Journal Entry 1

• Write a reflection on your understanding of
  variables.
• Describe at least one other the real-world
  cause-and-effect relationship.
• Identify the independent, dependent and control
  variables.

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Check you Understanding 1

• Identify the independent and dependent variables
  in each of the following

Situation Independent Variable Dependent Variable
A Jim says that the amount of lumber that he can cut depends upon the time that he spends in the woods
B Karina says that the amount of time that you spend walking to school depends mainly on the distance of your home from the school.
C Kim earns more money in a 6 hour shift that she earns in a 4 hour shift.
D Rob drives a transport truck. He is interested in the relationship between the amount of diesel fuel he uses and the size of the load in the trailer.
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Check you Understanding 1

• Complete the following table

Description Cause-and-Effect Relationship (Yes or No) Variables Variables
Description Cause-and-Effect Relationship (Yes or No) Dependent Variable Independent Variable
A The length of a candle and the amount of time it has been burning.
B The mark you get on a test and the time you spend studying.
C The speed of a car and the distance from the nearest gas station.
D The length of a movie and the admission price.
E The age of a car and its current value.
F The population of a community and its distance from the coast.
G The faster you drive and the number of speeding tickets you receive.
H The length of a beach and the size of the waves that crash on it.
I The number of pages of the test paper and the time permitted to write the exam.
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Check you Understanding 1

• Ski jumping is a popular event at the Winter
  Olympic Games. The following factors may affect
  the distance a skier jumps
• Length of the ramp
• Force with which the skier pushes to start
• Wind speed
• Wind direction
• Model of the skis
• Slope of the ramp.
• Draw a mind map to illustrate the relationships
  between the dependent and the independent
  variables.

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Check you Understanding 1
Factors the skier can control Factors the Jump Designer can control Factors outside the control of anyone

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Check you Understanding 1

• Taylor wants to see how the prices of various
  types of trees depend upon the height.

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Example of your bar graph