The Research Process: Coming to Terms

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Chapter 2

• The Research Process Coming to Terms

2006 Prentice Hall, Salkind.
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CHAPTER OVERVIEW

• From Problem to Solution
• All About Variables
• Other Important Types of Variables
• Hypotheses
• Samples and Populations
• The Concept of Significance

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WHAT IS RESEARCH ALL ABOUT, ANYWAY?

• Increasing our understanding of how and why we
  behave the way we do!!

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THE RESEARCH PROCESS COMING TO TERMS

• From Problem to Solution
• Noting an interesting question
• Stating the question in such a way that it can be
  answered
• The Language of Research

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ALL ABOUT VARIABLES

• A class of outcomes that can take on more than
  one value
• The more precisely a variable is measured, the
  more useful the measurement is

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DEPENDENT VARIABLES (DVs)

• The Outcomes of a Research Study
• Depends on the experimental treatment

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INDEPENDENT VARIABLES (IVs)

• Treatments or conditions under control of the
  researcher
• Levelsat least two different values of the IV
  must be present

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INDEPENDENT VARIABLES IN FACTORIAL DESIGNS
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THE RELATIONSHIP BETEWEEN INDEPENDENT AND
DEPENDENT VARIABLES WHAT MAKES GOOD VARIABLES?

• Independent Variable is not confounded
• Levels do not vary systematically with other
  variables
• Dependent Variable is sensitive to changes in the
  IV

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OTHER IMPORTANT TYPES OF VARIABLES

• Control VariableHas a potential influence on the
  DV
• Extraneous VariableHas an unpredictable impact
  on the DV
• Moderator VariableVariables related to IVs
  and/or DVs, and hiding the true relationship
  between IVs and DVs

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VARIABLESA SUMMARY
 
 
 
 
 
 
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HYPOTHESIS

• Reflects the general problem under study
• Restates the general problem in a form that is
  precise enough to allow testing

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NULL HYPOTHESIS

• States that there is no relationship between the
  independent and dependent variables under study
• Ho µ1 µ2
• Ho Null hypothesis
• µ1 Theoretical average of population 1
• µ2 Theoretical average of population 2

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PURPOSE OF NULL HYPOTHESIS

• A starting point for analysis
• Accepted as true absent other information
• Assumes that chance caused any observed
  differences
• Provides a benchmark for comparison

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THE RESEARCH HYPOTHESIS

• A statement of inequality
• A relationship exists between the independent and
  dependent variables

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DIRECTIONAL VS. NONDIRECTIONAL RESEARCH HYPOTHESES

• Nondirectional Research Hypothesis
• Groups are different, but direction is not
  specified
• H1 ?
• Directional Research Hypothesis
• Groups are different, and direction is specified
• H1 gt
• H1 lt

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PURPOSE OF RESEARCH HYPOTHESIS

• Directly tested during research process
• To compare against Null hypothesis

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DIFFERENCES BETWEEN NULL AND RESEARCH HYPOTHESES

• Research
• Inequality between variables
• Refers to sample
• Directly tested
• Stated using Roman symbols ( )
• Explicit

• Null
• Equality between variables
• Refers to population
• Indirectly tested
• Stated using Greek symbols (µ)
• Implied

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WHAT MAKES A GOOD HYPOTHESIS?

• Stated in declarative form
• Posits a relationship between variables
• Reflects theory or literature
• Brief and to the point
• Testable

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SAMPLES AND POPULATIONS

• The SAMPLE is a representative portion of a
  POPULATION
• The POPULATION is the entire group of interest
• Results from the SAMPLE should generalize to the
  POPULATION

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SIGNIFICANCE

• Observed differences (PROBABLY) result from the
  treatment and not from chance
• Why?
• Influences other than the treatment
• Significance level risk associated with not
  being 100 certain that Null hypothesis is
  incorrect