Understanding Theoretical Sampling Uses

Theoretical sampling is a method used primarily in qualitative research, particularly within the framework of Grounded Theory. It's an iterative process where data collection is guided by the emerging theory. The researcher continually collects, analyzes, and codes data, using the insights gained to decide what data to collect next and where to find it. This process aims to develop a theory with rich, well-developed concepts and properties.

Analysis of Options for Theoretical Sampling

Let's examine each option to determine when theoretical sampling is applied:

• A. Extension of the basic population is not known in advance: This is true for theoretical sampling. The focus is on developing theory, and the scope or boundaries of the population relevant to the theory become clearer and are refined during the research process, rather than being predetermined.
• B. Features of the basic population are not known in advance: This aligns with theoretical sampling. The goal is to discover properties and characteristics through data collection and analysis, so initial knowledge about the population's features is often limited and explored as the theory develops.
• C. Sample Size is not defined in advance: Theoretical sampling continues until theoretical saturation is reached – the point where collecting further data does not yield new insights or properties relevant to the emerging theory. Consequently, the sample size is not fixed beforehand but is determined by the analytical needs of the theory development.
• D. Repeated drawing of sampling elements with criteria to be defined again in each step: This accurately describes the iterative nature of theoretical sampling. Based on the emerging theory, researchers decide what additional data are needed and refine their sampling criteria for each subsequent data collection phase.
• E. Sampling is finished when the whole sample has been studied: This statement does not accurately reflect theoretical sampling. Theoretical sampling stops based on theoretical saturation, not simply upon completing the study of a pre-selected or fixed sample. The sample itself might evolve throughout the process.

Conclusion on Theoretical Sampling Application

Based on the principles of theoretical sampling, it is used when the extension and features of the relevant population are not fully known initially (A and B), when the sample size is not predetermined but determined by theoretical saturation (C), and involves iteratively refining sampling criteria as the theory develops (D). Option E describes a scenario contrary to the flexible and emergent nature of theoretical sampling.

Therefore, theoretical sampling is employed under the conditions described in options A, B, C, and D.