Scientific Method -What it is, How To Do It

							    Scientific Method – What it is,
                    How To Do It.




4
      Dependent and Independent
                       Variables
• Dependent variable depends on the
  independent variable.
  – Independent variables cause or effect changes
    in some other variable.
  – Dependent variables are changed or affected by
    the independent variable.
     Independent and Dependent
                      Variables
   Crime and Race      Income and Sentence

  Crime and Police     Crime Rate and Day of
      Presence                Week
Moon Phase and Crime    Single Parents and
                         Juvenile Record
 Domestic Abuse and       Completion of
  Economic Status      Correctional Program
                             and Age
          Independent and Dependent
                           Variables
If crime decreases as the result of decreases in street drug sales, then
crime is what type of variable?

If juries are more likely to impose the death penalty on the defendants
who are in gangs, then the death penalty is what type of variable?
If positive attitudes toward police increase as the result of increased
communication between police and citizens, then increased
communication between citizens and police is what type of variable?
If there is a cause and effect relationship between alcohol abuse and
spousal abuse, then spousal abuse is what type of variable?
                   Variable Attributes
• Male and female officers.
• New officers and experienced officers.
• College educated officers and non-college
  educated officers.
• High wages and low wages.
• High evaluation and low evaluation of
  employees.
         Directional Hypotheses and
                      Relationships
• The relationship may be positive or negative. For
  example as one variable increases so does the
  other go the same way, or it may go in an opposite
  way.
   – Example: As age increases to 24 crime involvement may increase,
     but above 24 involvement in crime may decrease.
   – Example: (Is this spurious) As the number of automobiles increase
     in a community the number of computer crimes increase.
   – Example: (Is this spurious) The crime of failure to appear
     decreases if the individual has a telephone.
    Exploratory vs. Confirmatory
                       Research
• Exploratory – don’t know if there is a
  relationship.
• Confirmatory – research to confirm that
  there is a relationship.
              Operational Definition
• The sex offender program has a recidivism
  rate of 12%.
  – What questions would you ask?
              Operational Definition
The department wishes to determine if there is
 a relationship between completion of the
 program and new arrests.
  !What has to be determined? What are the
   operational definitions needed?
The End