CDIS 455 CH. 1 Scientific Inquiry Study Notes

CHAPTER 1: SCIENTIFIC INQUIRY

Charis Powell, M.S., CCC-SLP
Fall 2021

SCIENTIFIC METHOD

  • The scientific method consists of the following steps:

    • State the problem

    • Formulate the hypothesis

    • Develop research method

    • Analyze results

    • Interpret Results

STATE THE PROBLEM

  • A clear statement describing the problem is essential for conducting a study, along with a rationale for its significance.

  • Research questions should reflect the goals of the study.

    • Example:

    • “Construction workers have poor hearing and/or hearing loss.”

FORMULATE THE HYPOTHESIS

  • A hypothesis serves as the best guess or prediction regarding the answer to the research question.

  • It should be supported by existing scientific literature as well as the researcher's personal experience.

    • Example Continued:

    • “Using hearing protection equipment will improve hearing abilities in construction workers.”

DEVELOP RESEARCH METHOD

  • This step involves specifying the research participants and creating a detailed plan to observe behaviors and record data.

    • Example Continued:

    • “Compare the hearing abilities of construction workers vs office workers and/or compare the hearing abilities of construction workers who do not use hearing protection vs those who do.”

ANALYZE RESULTS

  • After collecting data, analysis involves creating graphs, tables, and performing statistical tests.

    • Example Continued:

    • “A correlation coefficient of r=0.9 was found between profession and hearing abilities.”

INTERPRET RESULTS

  • The interpretation of results is guided by the initial research questions and hypotheses to determine if evidence supports or refutes the original hypothesis.

    • Example:

    • “There was a strong positive correlation between hearing loss/poor hearing abilities and profession.”

TYPES OF RESEARCH

  • There are two main types of research:

    • Basic Research

    • Aims to contribute new knowledge and understanding of theoretical concepts.

    • It investigates cause-and-effect relationships.

    • Applied Research

    • Focuses on solving social or clinical problems.

    • Aims to answer specific clinical questions and provide practical applications.

QUASI-EXPERIMENTAL VS EXPERIMENTAL

  • Experimental Research:

    • Involves random assignment of participants to at least two groups to determine who receives the treatment.

  • Quasi-Experimental Research:

    • Does not involve random assignment; instead, participants are assigned to groups based on pre-existing conditions.

    • Common in communication disorders research.

VARIABLES

  • Variables are essential concepts of interest for behavioral scientists.

  • They can take on different quantitative or qualitative values.

    • Examples of Variables:

    • Age (can be many values)

    • Coin toss results (heads vs tails, which are two categories)

  • Variables can be categorized as follows:

    • Dependent Variables

    • Independent Variables

    • The opposite of a variable is known as a constant, which does not change throughout the research.

INDEPENDENT VS DEPENDENT VARIABLES

  • Independent Variable:

    • Represents the cause and is manipulated by the researchers.

    • Not changed by other variables but manipulated by researchers.

    • Example:

    • In the statement “The amount of time you sleep affects your academic performance on a test,” the independent variable is:

      • “the amount of time you sleep.”

  • Dependent Variable:

    • Represents the effect that researchers wish to measure, typically a behavior influenced by the independent variable.

    • What you want to measure.

    • Example:

    • In the statement “The amount of time you sleep affects your academic performance on a test,” the dependent variable is:

      • “your academic performance on a test.”

OTHER TERMS/VARIABLES

  • Blinding Procedures:

    • These are measures that help ensure the integrity of the research process and reduce bias.

  • Active Variable:

    • This variable can be manipulated by the researcher.

  • Attribute Variable:

    • This variable cannot be manipulated.

  • Continuous Variable:

    • This variable has a numerical value and order, allowing for mathematical operations.

  • Categorical Variable:

    • This variable does not have a mathematical value or order.

  • Reliability:

    • This refers to the ability of a study to yield consistent results when repeated.

  • Validity:

    • This refers to the degree to which a study measures what it claims to measure.

THREATS TO VALIDITY

  • Internal Validity:

    • History: Effects of events occurring outside the study during an extended period.

    • Maturation: Changes in participants over time during a lengthy experimental treatment.

    • Attrition: Loss of subjects during the study.

    • Testing: Issues arising from testing participants more than once.

    • Instrument: Errors or inconsistencies in mechanical or electronic instruments used in measurements.

  • External Validity:

    • Factors affecting the generalizability of the study outcomes include pretest/posttest influences and experimenter effects, which may include mannerisms or appearance of the experimenter, and novelty effects that impact participants’ responses.