What factor influences sampling validity?

Sampling validity refers to how well a sample represents the population from which it is drawn. It is influenced primarily by the method used to select cases. A well-defined and appropriate sampling method ensures that every individual in the population has a fair chance of being selected, which enhances the representativeness of the sample. This represents true sampling validity, meaning that any conclusions drawn from the sample can be confidently generalized to the broader population.

On the other hand, the size of the sample can contribute to statistical power and generalizability to an extent, but it does not inherently guarantee that the sample is a valid representation of the population. The speed of data collection and researcher bias are also significant factors, but they relate more to the reliability and how the data is managed rather than the fundamental representation of the sample itself. Thus, the method used for case selection is the most direct influence on sampling validity.