Sampling technique/method

Sampling is the process of drawing a subset from a population. A sample is a finite part of a potentially infinite population. It is drawn for a more accurate reading of the characteristics of the population. Sampling methods and technics are generally categorized into three. These are: Convenient sampling, judgment sampling, and random samples. Convenient sampling is done when convenient elements of a population are selected for observation, while judgment sampling are subjectively based on the individual researcher’s subjective understanding of and familiarity with relevant characteristics of a population. Random sampling is the most popular sampling technique as it gives all members of the target population equal opportunity to be selected and be a representative sample. Random sampling can be systematic, in which case additional units are selected at evenly spaced intervals, until desired number of representative samples are completed. Random sampling can also be stratified. Here the population is first stratified and then samples selected independently from each stratum. Samples are randomly selected from each stratum in given number of units, based on proportions predetermined until number desired is complete. Lastly clustered sampling, where you have populations clustered probably based on geography and all members in the cluster sampled. E.g all teachers in a school, where all schools in a certain geographical area are seen as clusters. Schools are randomly selected to participate in the survey and all members sampled. Cluster sampling is said to be rife with biases as members of a cluster can be easily influenced by their peers.