Kvotointiotanta

Kvotointiotanta, also known as quota sampling, is a non-probability sampling method used in statistical research. It is designed to ensure that specific subgroups within a population are represented in the sample in proportions that match their prevalence in the population. This is achieved by setting quotas for each subgroup based on known population characteristics, such as age, gender, ethnicity, or socioeconomic status.

Unlike stratified random sampling, where individuals within each stratum are randomly selected, quota sampling allows the researcher to select individuals who meet the quota criteria in a non-random manner. This can be done through convenience sampling or snowball sampling within each quota group. The primary goal is to achieve a sample that mirrors the population's composition in terms of the chosen quota variables.

The advantage of quota sampling lies in its relative ease and cost-effectiveness, especially when a complete sampling frame for the population is unavailable or impractical to obtain. It can also be quicker to implement than probability sampling methods. However, due to its non-random nature, it is susceptible to selection bias. The researcher's choices in filling the quotas can inadvertently introduce systematic errors, making it difficult to generalize findings to the entire population with the same degree of confidence as with probability sampling. Therefore, quota sampling is often used in exploratory research or when strict probabilistic inference is not the primary objective.