Data Collecting, Organizing

1
Data Collecting, Organizing Analyzing
2
VARIABLES DATA TABLES
3

• In an experiment there are 2 types of variables
• INDEPENDENT VARIABLES
• DEPENDANT VARIABLES

4

• a VARIABLE is any factor, or thing that can
  change during your experiment

5

• a CONTROLED experiment only has 1 variable
  changing, or being tested
• Sometimes a control trial or group is used to
  compare experimental data to

6
INDEPENDENTVARIABLE

• This is the variable we can control in an
  experiment.
• Independent variables are set up ahead of time,
  before you start following your procedures

7
INDEPENDENTVARIABLE

• In a T table, or data table, this variable is
  on the left side.
• On a graph, this variable goes on the X axis

8
INDEPENDENT VARIABLE

• Examples of common Independent variables
• Time-measure every 30 seconds, every day, etc.
• Distance-measure every 0.5 meters, every 10.0 cm
• Amount-add 2.0 grams each trial

9
INDEPENDENTVARIABLE

• Your book calls the independent variable the
  MANIPULATED variable, because we manipulate or
  set it to our specifications

10
DEPENDENTVARIABLE

• This is the variable we have to observe in an
  experiment.
• Dependent variables are measured during the
  experiment, after you start following your
  procedures

11
DEPENDENTVARIABLE

• In a T table, or data table, this variable is
  on the right side.
• On a graph, this variable goes on the Y axis

12
DEPENDENT VARIABLE

• Examples of common Dependent variables
• Temperature-record the temperature
• Mass-find the mass of each object or substance
• Amount-count the resulting number of items

13
DEPENDENTVARIABLE

• Your book calls the dependent variable the
  RESPONDING variable, because it responds to the
  procedure you are following. We cant chose what
  the data will be.

14
GRAPHING NOTES
15
7 RULES OF GRAPHING

• Follow these simple rules for GREAT GRAPHS

16
RULE 1.

• 1. Always draw neat lines with a straight edge or
  ruler

17
RULE 2.

• Make your graph 1 full page in size.
• Small graphs are too difficult to read patterns
  or results of your experiment.

18
RULE 3.

• Label the x-axis (goes across the bottom of your
  graph)
• Label the y-axis ( the line that goes up down
  on the left side of your graph)

19
RULE 4.

• Label three places on your graph.
• 1. TITLE the graph descriptively
• WHAT DOES YOUR GRAPH SHOW US?

20
RULE 4.

• 2. label the x-axis with the independent variable
• this is the variable you pre-set before you began
  collecting data, on the left side of a T table
• common independent variables can be time, or
  distances
• Data points should be evenly spaced

21
RULE 4.

• 3. label the y-axis with the dependent variable
• this is the variable you measure when you begin
  collecting data, on the right side of a T table
• common dependent variables can be mass, or
  temperature
• Data points should be evenly spaced

22
RULE 5.

• Number the x and y axis with a regular numerical
  sequence or pattern starting with 0 to space out
  your data so it fills the entire graph
• examples 0, 5, 10, 15 . . .
• 0, 2, 4, 6, . ., 0, 0.5, 1.0, 1.5, 2.0

23
RULE 6.

• Number the x and y axis on the lines of the
  graph, not the spaces between the lines

24
RULE 7.

• If your graph shows more than one trial of data,
  or has more than 1 line, USE A KEY
• A key can be different colored lines, lines with
  different textures or patterns.

25
Choose the best graph for the data

• Pie chart- shows percentages and parts of a whole
• Bar graph- best for comparing data
• Line graph- best for looking at change over time
• Stem Leaf plot- comparing data that can also
  show mean, mode, and median

26
Statistical Analysis

• Mean- (average)- add up all the data divide
  that total by the number of data points ex.
  1,2,3,2,4,2 14 14/6 7/3 or 2.3
• Mode- number seen most often ex1,2,3,2,4,2
  mode is 2
• Median- middle value when data is placed in
  numerical order Ex. 1,2,2,2,3,4,5 odd
• ex1,2,2,2,3,4 even 224/22 median is 2
• Range- difference between the greatest and the
  smallest in the data set ex.1,2,2,2,3,4
  4-1 3 data vary over 3 values

27
How to change numbers into for pie charts.

• You can refer to your book on page 770.
• Determine the total number for your data add up
  all the values to get one number. 1,2,2,2,3,4
  14
• Divide each proportion by the total number. 1/14,
  2/14. 3/14, 4/14
• Multiply that decimal by 360. This will give the
  number of degrees that your pie piece should
  contain. Ex. 2/14 0.143 0.143 x 360 51.4
  degrees
• Use a protractor to measure the angle of each
  slice.
• To find the percentage take the number of degrees
  in the slice divide it by 360 and multiply the
  new number by 100. 51.4 / 360 0.143 x 100
  14.3

28
The End

• Good Luck and Happy Data Collecting!