Research Designs and Nonexperimental Research

Research Designs

• Research designs are classified into quantitative and qualitative categories.
• Quantitative designs are further categorized into experimental and nonexperimental designs.

Nonexperimental Research

• All nonexperimental research is descriptive in nature.
• There is no manipulation or control of variables in this type of research.
• Researchers simply describe phenomena as they exist.
• To ensure valid results, researchers must attempt to control extraneous variables by carefully selecting the study sample.
• Study limitations should also be considered.

Types of Nonexperimental Designs

• Survey Studies:

  • Self-report data are gathered from samples to describe populations regarding specific variables.
  • Researchers control the study through sampling techniques.
  • Surveys often collect data on subjects' attitudes, opinions, perceptions, and behaviors.
  • Common data collection methods include questionnaires, interviews, phone, mail, internet, and personal contact.
  • Surveys can be cross-sectional (studying subjects at one point in time) or longitudinal (studying subjects over an extended period).

• Correlational Studies:

  • These examine the strength and direction of relationships between two or more variables.
  • They analyze how changes in one variable relate to changes in another.
  • The strength and direction of a relationship are measured using a correlational coefficient.
  • A coefficient of +1.00 indicates a perfect positive correlation, while -1.00 signifies a perfect negative correlation.

• Correlational Coefficient:

  • A positive coefficient indicates that as one variable increases, the other increases.
  • A negative coefficient indicates that as one variable increases, the other decreases (an inverse relationship).

• Comparative Studies:

  • These examine the differences between groups on a dependent variable.
  • They do not involve manipulation of independent variables.
  • Comparative studies can be retrospective (looking back at past events) or prospective (following subjects forward in time).
  • In retrospective studies, the dependent variable is identified first, followed by an attempt to determine the independent variable.
  • In prospective studies, the independent variable is identified first, and subjects are followed to observe the effect on the dependent variable.

• Secondary Analysis Studies:

  • These studies involve analyzing data from previous studies or research.
  • They are cost-effective compared to collecting new data.
  • They are frequently used to address new research questions or hypotheses.
  • Data collection is usually the most time-consuming part of research, and secondary analysis has become popular for that reason.
  • Potential misrepresentation of results is a concern with secondary analysis studies.

• Other Nonexperimental Designs

  • Action studies
  • Evaluation studies
  • Meta-analysis studies
  • Methodological studies
  • Meta-synthesis studies