Sampling and parameters

sample

portion or subject of the larger population

population

collection of persons, things, or objects under study

variable

noted by a capital letter, is a characteristic of interest for each person or thing in a population

parameter

a number that is a property of the population

Statistic

A number that represents a property of the sample

Data

a set of observations or possible outcomes

sampling

gathering information about an entire population, often costs too much or is impossible

sample random sample

a sample of N subjects is selected in such a way that every possible sample of the same size N has the same chance of being chosen

Systematic sampling

select some starting point then select every Kth element in the population

convenience sampling

use results that are easy to get

stratified sampling

subdivide the population into at least 2 different subgroups that share characteristic, draw a sample from each group

cluster sampling

divide the population area into sections or clusters. Then randomly select some of those clusters, now choose all members from selected clusters.