SAMPLİNG FOR QUALİTATİVE RESEARCHAssoc. Prof. Dr. Şehnaz Şahinkarakaş

SAMPLİNG

Sample: any part of a population of individuals on whom information is obtained: students, teachers, young learners, etc.

Sampling: the process of selecting these individuals

SAMPLE SİZE

What is an appropriate sample size for qualitative research?

It depends: the size that adequately answers the research question

For single questions or detailed studies: single figure

For complex questions: larger samples

SAMPLE STRATEGİES

Three broad approaches:

Convenience sampling Purposive sampling Theoretical sampling

CONVENİENCE SAMPLE

Selecting the most accessible subjects

The least costy to the researcher

May result in poor quality data and lacks intellectual credibility

Why/When? Try to avoid; the least desirable method

PURPOSİVE SAMPLE (JUDGEMENT SAMPLE)

The most common

Researcher selects the most productive sample to answer the research question

If the subjects are known to the researcher, several strategies may be used to make the study more adventageous and to stratify the subjects (establishing sub-groups).

Selecting the strategy depends on the focus of inquiry researcher’s judgement (which one gives clearest

understanding of the phenomena)

DIFFERENT STRATEGIES IN PURPOSIVE SAMPLING

Maximum variation sample: broad range of subjects Why/When? To understand how a phenomenon is

seen and understood among different people, in different settings and at different times

Outliers (extreme cases): deviant sample to understand some unusual phenomenon Why/When? To develop a richer, more in-depth

understanding of a phenomenon and to lend credibility to one's research account

DIFFERENT STRATEGIES IN PURPOSIVE SAMPLING Critical case sample: (selecting a small number of

important cases) subjects who have specific experiences Why/When? When funds are limited

Key informant sample: subjects who have special expertise Why/When? To provide in depth information and

knowledge of a phenomenon of interest

Snowball sample: asking the subjects (e.g key informant) to recommend other useful subjects for the study. Why/When? When you feel you need more data to answer

your research question

DIFFERENT STRATEGIES IN PURPOSIVE SAMPLING

Confirming/Disconfirming sample: generally done during interpretation of the data; asking subjects who support emerging explanation and who disagree Why/When? To get additional examples that lend

further support, richness and depth to patterns emerging from data analysis (confirming cases)

To get examples that do not fit emergent patterns and allow the research team to evaluate rival explanations (disconfirming cases). This can help the research team understand and define the limitations of research findings

THEORETİCAL SAMPLE

The process of selecting a case for its potential representation of an important theoretical construct (i.e., incidents, slices of life, time periods, or people)

Why/when? When the research focuses on theory and concept development and the research team's goal is to develop theory and concepts that are connected to real life events and circumstances.