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SLP 696 Research Methods Applied & Basic

The following guide presents a collection of informational resources to support the graduate level research process


In research, variables are elements that can be manipulated, measured, or controlled. Understanding them is crucial for any study. Here's a simple breakdown of two fundamental types of variables:

  • Independent Variable (also known as Controlled or Manipulated Variable): This is the variable that you, the researcher, will change or manipulate. It's called "independent" because its variation is not dependent on other variables in your experiment.
    • For example, if you're studying the effects of sunlight on plant growth, the amount of sunlight would be your independent variable.
  • Dependent Variable (also known as Responding Variable): This is the variable that you measure in the experiment. It's called "dependent" because it depends on the changes you make to the independent variable.
    • Continuing with the plant growth example, the height of the plant would be the dependent variable, as it could change based on the amount of sunlight received.

In a research statement, the independent variable typically comes before the dependent variable.

  • For example, you might say: "This study examines how the amount of sunlight (independent variable) affects plant growth (dependent variable)." This helps clarify the cause-and-effect relationship you're investigating.


Here are some examples of independent and dependent variables in research related to Speech-Language Pathology (SLP):


Example 1: Stuttering Therapy

  • Independent Variable: Type of therapy used, e.g., [FLUENCY SHAPING OR STUTTERING MODIFICATION])
  • Dependent Variable: Frequency of stuttering events during conversation, e.g., [FREQUENCY OR RATE AND STUTTERING EVENTS]

Example 2: Aphasia Rehabilitation

  • Independent Variable: Types of rehabilitation exercises (e.g., word retrieval exercises, picture naming)
  • Dependent Variable: Improvement in language skills, measured using a standardized language assessment

Develop your Keyword Search Around your main topic, then the Independent and Dependent Variables:

For example:

1. Main topic:


2. Independent Variable(s):

("picture naming" OR "semantic mapping")

3. POSSIBLEY HELPFUL: Include terms to describe your Dependent Variable:

("Improvement in language skills" OR "language assessment" OR "language skills measurement" OR "standardized language assessment")

4. Put it all together:

​​​​​​​(Aphasia) AND (picture naming" OR semantic mapping) AND ("Improvement in language skills" OR "language assessment" OR "language skills measurement" OR "standardized language assessment")

Example 3: Early Language Development

  • Independent Variable: Age of exposure to a second language (e.g., before age 3, between ages 4-6, etc.)
  • Dependent Variable: Proficiency in second language skills, such as vocabulary size or grammatical accuracy

Example 4: Hearing Aids and Speech Comprehension

  • Independent Variable: Use of hearing aids (e.g., with or without hearing aids)
  • Dependent Variable: Speech comprehension scores in noisy environments

Example 5: Speech Sound Disorders in Children

  • Independent Variable: Intervention approach (e.g., traditional articulation therapy, phonological process therapy)
  • Dependent Variable: Number of speech sound errors made in conversation

Example 6: Telepractice vs. In-Person Therapy

  • Independent Variable: Mode of therapy delivery (e.g., telepractice or in-person)
  • Dependent Variable: Client satisfaction rates or treatment outcomes