220.127.116.11 Limitations of Probability Sampling
Despite the great advantages of probability sampling techniques mentioned above it has certain limitations because of which also non-probability sampling is used in practice. These limitations are
1. Probability sampling requires a very high level of skill and experience for its use
2. It requires a lot of time to plan and execute a probability sample
3. The costs involved in probability sampling are generally large as compared to non-probability sampling
Non probability sampling
Non–random sampling is a process of sample selection without the application of randomization. In other words, a non-random sample is selected on a basis other than the probability consideration such as convenience, judgment etc.
The most important difference between random and non-random sampling is that the pattern of sampling variability can be ascertained in case of random sampling, whereas there is no way of knowing the pattern of variability in the process in non-random sampling.
Some of the important popularly used sampling methods that are are discussed in the following sections.