Scott Bradley, Ph.D.

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Research in Communicative Disorders

• Scott Bradley, Ph.D.
• University of Wisconsin-Whitewater

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Introduction (chap 1)

• Why Do We Study Research?
• Types of Research
• The Research Study

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Why Do We Study Research?

• Consumers of Research
• Producers of Research

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Types of Research

• Basic vs. applied research
• Experimental vs. descriptive research

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The Research Study

• Introduction
• Title
• Abstract
• Introduction/review of the literature
• Statement of the problem

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The Research Study (cont.)

• Method
• Subjects
• Materials/Instrumentation
• Procedure
• Results
• Conclusions and discussion

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Research Strategies (chap 2)

• Variables in Empirical Research
• Experimental Research
• Descriptive Research

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Variables in Empirical Research

• Independent Dependent Variables
• Active Attribute Variables
• Continuous and Categorical Variables

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Independent Dependent Variables

• Independent variable is presumed cause of the
  dependent variable.
• Independent variable is controlled by
  experimenter
• Dependent variable is what is measured.

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Active Attribute Variables

• Active variables are variables that can be
  manipulated.
• Active variables are usually associated w/
  experimental research
• Attribute variables are attributes which describe
  a specific group or condition and can not be
  actively manipulated
• Attribute variables are usually associated w/
  descriptive research.

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Continuous and Categorical Variables

• Continuous
• Range along a continuum
• E.g., age, frequency, dB, rating scale, height
• Categorical
• Separate categories
• E.g., male v. female, conductive loss v. sensori
  neural loss, disordered language v. normal
  language.

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Experimental Research

• Characteristics
• Must have a purpose, research quest. or
  hypothesis.
• Control occurrence of events
• Findings can be replicated
• Variables may be manipulated.

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Experimental Research (cont.)

• Types of experimental research
• Bivalent experiments
• Multivalent experiments
• Parametric experiments

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Bivalent experiments

• Must contain only two levels or categories of an
  independent variable.
• E.g., .5 mg v. .10 mg, males v. females, low
  pitch v. high pitch, etc.
• Can lead to erroneous results if an artificial
  dichotomy exists.

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Multivalent experiments

• More than two levels or categories of the
  independent variable.
• Provides a more complete picture of the effects
  of the independent variable.

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Parametric experiments

• Simultaneous effect of more than one independent
  variable.
• Has the advantage of looking at more than one
  factor and to examine interaction between the
  independent variables.

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Descriptive Research

• Differences between descriptive and experimental
  research.
• Attributes
• Does not lead to cause effect relationship
• Can be as effective as experimental research
  under certain circumstances

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Descriptive Research (cont.)

• Comparative Research
• Developmental Research
• Correlational Research
• Surveys
• Case Study, Single Subject, and Retrospective
  Research

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Comparative Research

• Probably the most common type of descriptive
  research
• Problem w/ cause and effect
• Problem with uncontrolled variables

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Developmental Research

• Examines effect of age or maturation.
• Designs
• Cross-sectional
• Longitudinal
• Semi-longitudinal

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Correlational Research

• Examines the relationship between two or more
  variables
• Purpose of correlational research
• Examine how closely one variable relates to
  another
• Ability to predict one variable from another

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Scatterplot
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Surveys

• Purpose
• Questionnaires v. interviews
• Pros and Cons

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Case Study, Single Subject, Retrospective

• Case Study
• Single subject
• Retrospective

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Last Slide