🧠 Data Collection and Sampling Methods in Qualitative Research

📌 Key terms

TermDefinition
SamplingThe process of selecting participants or cases to study from a population.
Purposive SamplingSelecting participants based on specific characteristics or relevance to the research question.
Snowball SamplingExisting participants recruit future participants through their social networks.
Convenience SamplingSelecting participants based on availability and willingness.
Quota SamplingEnsuring sample proportions match characteristics in the population (e.g., age, gender).
Theoretical SamplingSampling guided by emerging theory—used in grounded theory research.
Semi-Structured InterviewA flexible interview with open-ended questions based on a guiding schedule.
Unstructured InterviewOpen conversation that explores topics freely with minimal guidance.
Focus GroupA group interview led by a facilitator, exploring collective perspectives.
Participant ObservationThe researcher becomes part of the setting to observe behaviors and interactions.
Non-Participant ObservationThe researcher observes without engaging with participants.
Naturalistic ObservationObservation of behavior in real-life contexts without manipulation.
Field NotesDetailed written accounts of observed events, contexts, and reflections.
Reflexive JournalA diary in which the researcher records personal thoughts and methodological decisions.

📌 Notes

Purpose of Qualitative Data Collection

  • Focuses on in-depth understanding of experiences and social interactions.
  • Seeks rich, descriptive data to interpret meanings rather than measure variables.
  • Methods are flexible and iterative—data collection and analysis often occur simultaneously.

📌 Comparison with Quantitative Research

MethodDescriptionStrengthsLimitations
Interviews (Semi-Structured/Unstructured)Open-ended discussions exploring individual perspectives.Deep insight into thoughts, flexible, builds rapport.Time-consuming, interviewer bias possible.
Focus GroupsGroup discussions guided by a moderator.Generates diverse opinions, stimulates discussion.Social desirability bias, group dynamics may suppress dissent.
Participant ObservationResearcher actively engages in setting to observe behavior.High ecological validity, contextual detail.Risk of researcher bias, ethical issues of consent.
Non-Participant ObservationResearcher observes from outside.Reduces interference, useful in public settings.Limited insight into motives.
Case StudiesIn-depth study of one individual or group.Provides comprehensive understanding.Not generalizable; prone to researcher bias.
Document and Content AnalysisSystematic analysis of existing records, media, or text.Non-intrusive, historical context possible.Interpretation bias, lack of context.

Ensuring Credibility in Data Collection

  • Ensure ethical transparency—confidentiality, informed consent, and respect.
  • Use triangulation: multiple sources/methods.
  • Maintain reflexivity journals and field notes.
  • Conduct member checks to verify participants’ perspectives.

🔍Tok link

  • What counts as “truth” in qualitative findings if data are shaped by both participants and researchers?
  • This challenges the idea that knowledge can ever be entirely objective.

 đŸŒ Real-World Connection

  • Qualitative sampling is key in cross-cultural studies, healthcare research, and education, where understanding context and participant experience is essential for effective intervention design.

❤️ CAS Link

  • Students can engage in local community interviews (e.g., on stress, motivation, or social belonging) and reflect on how purposive or snowball sampling ensures ethical inclusivity.

🧠  IA Guidance

  • Even though the IA uses quantitative data, students can improve design validity by borrowing qualitative practices such as clear sampling rationale and pilot testing of instruments.

🧠 Examiner Tips

  • Be specific: use correct terminology (e.g., “semi-structured interviews,” not “normal interviews”).
  • Always connect method + purpose + example study.
  • Be prepared to compare qualitative sampling (purposive, snowball) vs. quantitative sampling (random, stratified).