Ickesannolikhetsurval

Ickesannolikhetsurval, which translates from Swedish to "non-probability sampling," is a method of selecting a sample from a population where the selection is not based on random chance. Instead, the researcher uses their own judgment or convenience to choose participants. This contrasts with probability sampling, where every member of the population has a known, non-zero chance of being selected.

There are several types of non-probability sampling. Convenience sampling involves selecting individuals who are readily available and easy to access. Quota sampling aims to create a sample that reflects the proportions of certain characteristics found in the population, but selection within those quotas is not random. Judgmental or purposive sampling involves the researcher using their expertise to select participants they believe will be most informative for the study. Snowball sampling is used when the target population is difficult to reach; initial participants refer the researcher to others who might also qualify.

Non-probability sampling is often used when random sampling is impractical, too expensive, or when the researcher has specific goals that do not require statistical generalization to the entire population. It can be useful for exploratory research, qualitative studies, or when studying hard-to-reach populations. However, a significant limitation is that the results from non-probability samples cannot be statistically generalized to the broader population with the same confidence as probability samples. This is because the non-random selection process can introduce bias, making the sample unrepresentative.