Sampling terminology

Sampling has its own terms that it uses
Population
    A population is any entire collection of people, animals, plants or things
from which we may collect data.
   It is the entire group we are interested in, which we wish to describe or draw
conclusions about.
     It is important that the investigator carefully and completely defines the
population before collecting the sample, including a description of the members to be included

Sample
   A sample is a group of units selected from a larger group (the population)
    A sample is generally selected for study because the population is too large
to study in its entirety.
     The sample should be representative of the general population.
    Also, before collecting the sample, it is important that the researcher
carefully and completely defines the population, including a description of
the members to be included.

 sample size
The number of students, families or electors from whom you obtain the
required information is called the sample size and is usually denoted by
the letter n.
 Sampling design
The way you select students, families or electors is called the sampling
design or sampling strategy.
Parameter
A parameter is a value, usually unknown (and which therefore has to be
estimated), used to represent a certain population characteristic.
   Sampling unit
Each student, family or elector that becomes the basis for selecting your
sample is called the sampling unit or sampling element.
Sampling Frame
A list identifying each student, family or elector in the study population is
called the sampling frame. If all elements in a sampling population cannot be
individually identified, you cannot have a sampling frame for that study
population.
 Sample Statistics
Your findings based on the information obtained from your respondents
(sample) are called sample statistics. Your sample statistics become the basis
of estimating the prevalence of the above characteristics in the study
population.
Population mean
Your main aim is to find answers to your research questions in the study
population, not in the sample you collected information from. From sample
statistics we make an estimate of the answers to our research questions in the
study population. The estimates arrived at from sample statistics are called
population parameters or the population mean.