Different types of Sampling 

Sample

            A subset of the population being studied from which data is actually collected. A good sample accurately represents all kinds of elements for members in proportion to their presence in the population.

Sampling techniques

Sampling techniques of the process by which the subset of the population from which you will collect data are chosen. There are two general types of sampling techniques:

●       Probability sampling

●       Non probability sampling

Figure 1

Figure showing Probability sampling

 

Figure 2

Figure showing Non Probability Sampling

 

Table 1

Table showing the differences of Probability and Non Probability Sampling

 

KEY	PROBABILITY SAMPLING	NON-PROBABILITY SAMPLING
Alternately known as	Random sampling	Non-random sampling
Basis of selection	Randomly	Arbitrarily
Opportunity of selection	Fixed and known	Not specified and unknown
Research	Conclusive	Exploratory
Result	Unbiased	Biased
Method	Objective	Subjective
References	Statistical	Analytical

 

Snowball sampling

Snowball sampling is a non probability sampling technique that is used by researchers to identify potential subject in studies your subject are hard to locate.

●       Snowball is a type of non probability sampling technique

●       Snowball sampling is choosing the participants to find more participants for making a sample group.

●       Mostly researchers used this sampling technique where participants are difficult to locate in a General population

●       Snowball sampling technique works as a chaining system

●       Participants refer other participants

 There are two important things to remember in snowball sampling

To find one or more research participants for research

To take reference of participant to get more sample size in research

PURPOSIVE SAMPLING

Purposive sampling is also known as Judgmental, subjective or selective sampling, reflects a group of sampling techniques that rely on the judgment of the researcher.

Meaning and Objectives

●       Method in which elements are chosen from among the whole population based on the purpose of study

●       Researcher with his good decisions and appropriate policy, choose these elements which are meant for fulfilling the research objective.

Reference

1. https://www.scribbr.com/methodology/snowball-sampling/