IGCSE Development Studies: Specimen Questions with Answers 37 - 38 of 98

Question 37 (2 of 7 Based on Passage)

Short Answer▾

Distinguish Between Random Sampling and Non-Probability Sampling

Distinguish between Random Sampling and Non-Probability Sampling
S. no.	Random Sampling	Non-probability sampling
1.	It is the method in which elements of the population get an equal opportunity to be selected as a representative sample.	It is a method in which elements of the population are not pre-specified and have unequal opportunity of being a sample
2.	Selection process is involved is random sampling	Selection process involved is arbitrary
3.	Results are unbiased due to conclusive nature	Results are biased due to exploratory nature
4.	Basis of inference in statistical in nature	Basis of inference is analytical in nature.

Short Answer▾

Explain two methods of choosing sampling.

Stratified sampling: It divides the population by certain characteristics into different homogeneous strata (like, PhD students, masters, bachelors) . Elements in each stratum is homogeneous but are heterogeneous across. After selecting the strata, a simple random sampling or systematic random sampling is done on each stratum to the proportion of each strata.
Quota Sampling: In quota sampling the population is first segmented into mutually exclusive sub-groups, as in stratified sampling. Then the judgement of the investigator is used in selecting the subjects or units from each segment in a proportion. E. g. Interview took sample of 200 females and 400 males between the age group 35 - 55.