Sampling in qualitative research. Purposeful and theoretical sampling; merging or clear boundaries?

Area of Science:

• Qualitative Research Methodology
• Nursing Research

Background:

• Qualitative sampling methods present significant complexity and overlap in literature.
• Purposeful and theoretical sampling are frequently misunderstood and used interchangeably.
• Ambiguity in sampling terminology hinders methodological rigor in nursing studies.

Purpose of the Study:

• To critically analyze purposeful and theoretical sampling techniques.
• To clarify the distinct applications of theoretical sampling in nursing research.
• To enhance understanding of sampling differences for novice researchers.

Main Methods:

• Critical analysis of existing literature on qualitative sampling.
• Examination of the terminology and underlying assumptions of purposeful and theoretical sampling.
• Focus on clarifying distinctions relevant to nursing research.

Main Results:

• Identified significant confusion and interchangeable use of purposeful and theoretical sampling terms.
• Highlighted how lack of shared meaning impacts nursing research methodology.
• Provided a critical analysis to differentiate the two sampling approaches.

Conclusions:

• Clarifying sampling terminology is crucial for improving the quality of nursing research.
• Distinguishing between purposeful and theoretical sampling enhances methodological precision.
• This analysis aims to reduce confusion and support more robust qualitative nursing studies.