Population
is a group of people and the dwelling, locations and environments that that group of people lives in.Population can be defined by age, ethnicity, type of housing, birthplace pr location. "he size of population size can refer to the total amount of people that live in that around you are defining." There are three different ways to measure population is actual counts of people, estimates of changes in actual counts due to population growth from births, deaths and migration, and projections of changes to future numbers of inhabitants.


Sampling is a finite part of a statistical population whose properties are studies, to gain information about the population. Sampling can also be defined as a act, process, or technique of selection a suitable sample, or a representative part of a population. People use sampling to draw conclusions about populations from samples. There are three different types of sampling one is “the convenient sampling results when the more convenient elementary units are chosen from a population for observation” the second type of sampling is “A judgment sample is obtained according to the discretion of someone who is familiar with the relevant characteristics of the population,” the last one is “A random sample allows a known probability that each elementary unit will be chosen. For this reason, it is sometimes referred to as a probability sample. This is the type of sampling that is used in lotteries and raffles.” There are different forms of random sampling :
  • simple random sample - "A simple random sample is obtained by choosing elementary units in search a way that each unit in the population has an equal chance of being selected."
  • systematic random sample - "A systematic random sample is obtained by selecting one unit on a random basis and choosing additional elementary units at evenly spaced intervals until the desired number of units is obtained. For example, there are 100 students in your class."
  • stratified sample - "A stratified sample is obtained by independently selecting a separate simple random sample from each population stratum."
  • cluster sample - "A cluster sample is obtained by selecting clusters from the population on the basis of simple random sampling. The sample comprises a census of each random cluster selected."




References:

1. Sustainable Development Programme of Action, "What is population? ." 13.10.2008 7 Nov 2008 <http://www.population.govt.nz/intro-to-popn/what-is-population.htm>.


2. Fridah , Mugo. "Sampling In Research." 2001 1. 7 Nov 2008
<http://www.socialresearchmethods.net/tutorial/Mugo/tutorial.htm>. Fridah , Mugo. "Sampling

I3. n Research." 2001 1. 7 Nov 2008
<http://www.socialresearchmethods.net/tutorial/Mugo/tutorial.htm>. Webster, M. (1985). Webster’s nith new collegiate dictionary. Meriam - Webster Inc.