Which of the following are NOT probability sampling techniques? 

A. Simple Random 

B. Stratified 

C. Snowball 

D. Cluster 

E. Convenience 

Choose the correct answer from the options given below: 

the correct answer is:Option 2) C and E only

Important PointsSampling: The concept of sampling involves selecting a portion (sample) from a bigger group (the sampling population). There are three methods of sampling in research:

1. Random/Probability Sampling
2. Non-random/Non-probability Sampling
3. ‘Mixed’ Sampling

 Random/Probability Sampling: In this type, each element in the population has an equal and independent chance of selection in the sample.

Non-Random/Non-Probability Sampling Designs: These designs do not operate on the principle of randomization rather these are used when the number of elements in the population is either unknown or cannot be individually identified.

 Simple Random -

• This is a probability sampling technique where each member of the population has an equal chance of being selected.
• It is a valid probability sampling method.

 Stratified -

• This is a probability sampling technique where the population is divided into subgroups (strata) based on certain characteristics, and then samples are randomly selected from each stratum.
• It is a valid probability sampling method.

 Snowball -

• This is a non-probability sampling technique where initial participants are chosen, and then additional participants are recruited through referrals.
• It does not guarantee that each member of the population has a known, non-zero probability of being selected. So,
• it is not a probability sampling method.

 Cluster -

• This is a probability sampling technique where the population is divided into clusters, and then a random sample of clusters is selected, and all members within the selected clusters are included in the sample.
• It is a valid probability sampling method.

 Convenience -

• This is a non-probability sampling technique where the sample is chosen based on what is convenient or readily available.
• It does not guarantee that each member of the population has a known, non-zero probability of being selected.
• So, it is not a probability sampling method.

So, the correct answer is: C and E only C. Snowball and E. Convenience are not probability sampling techniques.