Which of the following sampling methods are probability based? a) Cluster sampling b) Quota sampling c) Systematic sampling d) Dimensional sampling e) Stratified sampling Choose the most appropriate answer from the options given below:

Non- probability Sampling Method

Probability Sampling Method

• It is one in which there is no way of assessing the probability of the element or group of elements, of the population being included in the sample.
• Non-probability sampling methods are those that provide no basis for estimating how closely the characteristics of the sample approximate the parameters of the population from which the sample had been obtained. This is because the non-probability samples do not use the techniques of random sampling.
• Important techniques of non-probability sampling methods are Haphazard, Accidental, or Convenience Sampling, Quota Sampling,  Purposive sampling, Snowball sampling. 

• Probability sampling methods are those that clearly specify the probability or likelihood of inclusion of each element or individual in the sample.
• These are free of bias in selecting sample units.
• They help in the estimation of sampling errors and evaluate sample results in terms of their precision, accuracy and efficiency, and hence, the conclusions reached from such samples are worth generalization and comparable to the similar populations to which they belong.
• Major probability sampling methods are simple random sampling, stratified random sampling, and Cluster sampling, and Systematic sampling.