2 What is a sample ?A sample is a fractional part of the population selected for investigationSampling is then, the act of taking sample from the population.Population is defined as the entire collection of all persons, objects or items concerning a specific area of investigation or study.If data are collected from a fractional part of the population and the result derived from it is used in predicting or inferring the population, it is known as Inductive or Inferential statistics.
3 Cont.A sampling frame is simply a numbered list of all the items in the population. A sampling frame should have the following characteristics :Completeness/No omissionAccuracyConvenienceNon-duplication
4 FACTORS THAT DETERMINE THE CHOICE OF SAMPLING TECHNIQUE the desire to avoid biasness in the selection procedure.secondly, to ensure representativeness of the population andthirdly, to achieve the maximum precision for a given out lay of resources.
5 CATEGORIES OF SAMPLING TECHNIQUES Sampling methods or techniques can be classified into two main categories:Random sampling andNon–random sampling.
6 TYPES OF RANDOM SAMPLING TECHNIQUES There are five types of random sampling:-Simple random,Systematic,Stratified,Cluster andMulti–stage.
7 NON-RANDOM SAMPLINGAny method of selecting sample from the population that does not embody the features of randomness is known as non-random sampling.QUOTA SAMPLINGThis is a method whereby the population is divided into homogeneous units just like stratified sampling, but the main difference is that, the selection of units within each stratum is not random