Collection of Data — Economics STD 11 Commerce — Question

Random Sampling:There are two methods of random sampling.

1. Unrestricted Random Sampling
2. Restricted random sampling.

Unrestricted Random Sampling:

1. Lottery Method.
2. Use of Random Number Tables.

Restricted Random Sampling:

1. Stratified Sampling/ Mixed Sampling.
2. Cluster Sampling.
3. Systematic Sampling.

Non-Random Sampling:

1. Quota Sampling.
2. Judgment Sampling/ Purposive.
3. Sampling/ Deliberate Sampling.
4. Convenience Sampling/ Availability.

Sampling: Cluster sampling is a sampling technique used when "natural" but relatively homogeneous groupings are evident in a statistical population. It is often used in marketing research. In this technique, the total population is divided into these groups (or clusters) and a simple random sample of the groups is selected. Then the required information is collected from a simple random sample of the elements within each selected group. This may be done for every element in these groups or a subsample of elements may be selected within each of these groups. A common motivation for cluster sampling is to reduce the total number of interviews and costs given the desired accuracy. Assuming a fixed sample size, the technique gives more accurate results when most of the variation in the population is within the groups, not between them.