Question

ix. What is the difference between probabilistic and non-probabilistic sampling?

x. What are some potential risks when using fishbowl methods to select a simple random sample?

xi. Mention the difference between sampling with replacement and sampling without replacement

xii. Contrast simple random sampling with systematic sampling.

Answer 1

Answer : ( ix )

Probabilistic sampling is when the probability of each member of a population has a determinable probability of bering selected. On the other hand, non-probabilistic sampling is when the probability for an individual of a given population to be selected is unknown.

Probabilistic sampling is alternately known as random sampling. On the other hand, non-probabilistic sampling is alternately known as non-random sampling.

Opportunity of selection of probabilistic sampling is fixed and known. On the other hand, opportunity of selection of non-probabilistic sampling is not specified and unknown.

Hypothesis of probabilistic sampling is tested. On the other hand, hypothesis of non-probabilistic sampling is generated.

Probabilistic sampling method is objective. On the other hand, non-probabilistic sampling method is subjective.

The methods of probabilistic sampling are simple random sampling, stratified sampling, cluster sampling and systematic sampling.   On the other hand, non-probabilistic sampling convenience sampling, quota sampling, judgment sampling and snowball sampling.

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Answer : ( xii )

Simple random sampling : Each member of the population has an equal chance of being chosen. Example : The name of each student in your class is put in a hat and 5 names are drawn.

Advantages:

• Easy to implement.

• Requires little knowledge of the population in advance.

Disadvantages:

•  Imprecise relative to other designs if the population is heterogeneous.

•  More expensive than other designs if entities are clumped and the cost to travel among units is appreciable.

and

Systematic sampling : Every nth member of the population is chosen. Example : Every 100th name in the telephone directory is chosen.

Advantages:

• Easy to implement.

• Maximum dispersion of sample units throughout the population.

• Requires minimum knowledge of the population.

Disadvantages:

• Less protection from possible biases.

• Can be imprecise and inefficient relative to other designs if the population being sampled is heterogeneous.