Presentation on theme: "BY OLUFOLABO.O.O SAMPLING METHODS OR TECHNIQUES. What is a sample ? A sample is a fractional part of the population selected for investigation Sampling."— Presentation transcript:
What is a sample ? A sample is a fractional part of the population selected for investigation Sampling 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.
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 omission Accuracy Convenience Non-duplication
FACTORS THAT DETERMINE THE CHOICE OF SAMPLING TECHNIQUE the desire to avoid biasness in the selection procedure. secondly, to ensure representativeness of the population and thirdly, to achieve the maximum precision for a given out lay of resources.
CATEGORIES OF SAMPLING TECHNIQUES Sampling methods or techniques can be classified into two main categories: Random sampling and Non–random sampling.
TYPES OF RANDOM SAMPLING TECHNIQUES There are five types of random sampling:- Simple random, Systematic, Stratified, Cluster and Multi–stage.
NON-RANDOM SAMPLING Any method of selecting sample from the population that does not embody the features of randomness is known as non-random sampling. QUOTA SAMPLING This 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