Data Collecting Organizing Analyzing VARIABLES DATA TABLES w

Data Collecting, Organizing & Analyzing

VARIABLES & DATA TABLES

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

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

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

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

INDEPENDENT VARIABLE w In a “T” table, or data table, this variable is on the left side. w On a graph, this variable goes on the X axis

INDEPENDENT VARIABLE w 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

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

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

DEPENDENT VARIABLE w In a “T” table, or data table, this variable is on the right side. w On a graph, this variable goes on the Y axis

DEPENDENT VARIABLE w 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

DEPENDENT VARIABLE w Your book calls the dependent variable the RESPONDING variable, because it responds to the procedure you are following. We can’t chose what the data will be.

GRAPHING NOTES

7 RULES OF GRAPHING w Follow these simple rules for GREAT GRAPHS

RULE # 1. w 1. Always draw neat lines with a straight edge or ruler

RULE # 2. w Make your graph 1/2 page or 1 full page in size. w Small graphs are too difficult to read patterns or results of your experiment.

RULE # 3. w Label the x-axis (goes across the bottom of your graph) w Label the y-axis ( the line that goes up & down on the left side of your graph)

RULE # 4. w Label three places on your graph. w 1. TITLE the graph descriptively w WHAT DOES YOUR GRAPH SHOW US?

RULE # 4. w 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

RULE # 4. w 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

RULE # 5. w 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

RULE # 6. w Number the x and y axis on the lines of the graph, not the spaces between the lines

RULE # 7. w If your graph shows more than one trial of data, or has more than 1 line, USE A KEY w A key can be different colored lines, lines with different textures or patterns.