Non-probability sampling designs also called qualitative or non-random are the designs where the probability of each and every person being selected to be part of the sample is unknown. This technique deals with information rich sample based on the problem of the study.
This sampling technique is associated with qualitative research where generalizations is not the end result. There are four main non-probability designs. These are convenience, purposive, quota and snowball. This lesson will discuss the 4 designs in details.