Échantillonnage

Échantillonnage is the process of selecting a subset of individuals or items from a larger population to study. This subset, known as a sample, is chosen in a way that is intended to be representative of the entire population. The goal of sampling is to infer characteristics of the population based on the analysis of the sample, without having to collect data from every single member of the population. This is particularly useful when dealing with large or inaccessible populations, or when conducting studies that are time-consuming or expensive.

There are various methods of sampling, broadly categorized into probability sampling and non-probability sampling. Probability sampling techniques involve random selection, ensuring that each member of the population has a known, non-zero chance of being included in the sample. Examples include simple random sampling, stratified sampling, and cluster sampling. These methods are preferred for their ability to minimize sampling bias and allow for statistical generalization.

Non-probability sampling, on the other hand, does not rely on random selection. Instead, it uses subjective judgment or convenience to select the sample. Common non-probability methods include convenience sampling, quota sampling, and snowball sampling. While these methods can be quicker and less costly, they are more prone to bias and limit the extent to which findings can be generalized to the population. The choice of sampling method depends on the research objectives, available resources, and the nature of the population being studied.