Question

Follow the instructions carefully. [20 marks] Question Sampling is the process of selecting a representative subset of observations from a population to determine characteristics (i.e. the population parameters) of the random variable under study. Probability sampling includes all selection methods where the observations to be included in a sample have been selected on a purely random basis from the population. Briefly explain FIVE (5) types of probability sampling.

Answer 1

FIVE (5) types of probability sampling.:

(1) Simple Random Sampling (SRS): The samples are selected in a process that gives all the individuals in the population equal chances of being selected. using randomization techniques such as computer software or mechanical ways. Thus the items are selected entirely by chance, eliminating sampling bias.

(2) Stratified Random Sampling (also called Proportional Random Sampling): All the subjects in the population are grouped into mutually exclusive different classes, called strata. Final items for the sample are selected through using randomization techniques such as computer software or mechanical ways from each stratum.

(3) Systematic Random Sampling: First, each member of the population is identified by a serial number. Then, start with a random item. Individuals are selected at regular intervals from the sampling frame. This method of sampling is different from Simple Random Sampling because in Systematic Random Sampling every possible sample of n elements is not equally likely.

(4) Cluster Sampling: The population is divided into several clusters. Then number of clusters are selected randomly. All items of each selected clusters constitute the desired sample.

(5) Multistage Sampling: Sample is selected by using combinations of different sampling methods. For example: Stage 1: Use Cluster Sampling to select clusters from the population. Stage 2: Use Simple Random Sampling to select subset of elements from each cluster for the final sample.