Dependent v. Independent Variables

1
Dependent v. Independent Variables

• Whats the difference?

2
What is a Variable?

• Simply, something that varies.
• Specifically, variables represent persons or
  objects that can be manipulated, controlled, or
  merely measured for the sake of research.
• Variation How much a variable varies. Those
  with little variation are called constants.

3
Examples of Variables

• In the recent GOP sweep of the House and Senate,
  variables (or factors) that may have played a
  part would include

• Voter Turnout
• Party Message
• of Open Seats
• Redistricting
• of Incumbents
• Wellstone Funeral

4
Independent Variables

• These variables are ones that are more or less
  controlled.
• Scientists manipulate these variables as they see
  fit.
• They still vary, but the variation is relatively
  known or taken into account.
• Often there are many in a given study.

5
Dependent Variables

• Dependent variables are not controlled or
  manipulated in any way, but instead are simply
  measured or registered.
• These vary in relation to the independent
  variables, and while results can be predicted,
  the data is always measured.
• There can be any number of dependent variables,
  but usually there is one to isolate reason for
  variation.

6
Independent V. Dependent

• Intentionally manipulated
• Controlled
• Vary at known rate
• Cause

• Intentionally left alone
• Measured
• Vary at unknown rate
• Effect

7
Example What affects a students arrival to
class?

• Variables
• Type of School
• Liberals Arts v. University
• Type of Student
• Athlete? Gender? GPA?
• Time
• Bedtime, Waking, Arrival
• Mode of Transportation

8
Graphing Dependent v. Independent Variables

• The dependent variable is placed on the y-axis,
  while the independent variable is placed on the
  x-axis.
• Example Stock Market Graph

9
Sources

• Stat Soft, Inc. http//www.statsoftinc.com/textboo
  k/esc.html
• Datatrend Software http//www.datatrendsoftware.co
  m/datatypes1.html
• ARG! Cartoon Animation Studio http//artie.com/cre
  dits.htm