HLTB15 WINTER 2013
LECTURE # 7 – SAMPLING METHODS QUESTIONS
What is sampling?
Sampling is the process of taking a small group of members from a larger population
in order to produce a sample that is representative (or as close as you can make it)
of the larger population you wish to study.
What are the advantages of sampling?
It is more COST EFFECTIVE and LESS LABOUR INTENSIVE in terms or resources
and human input
What are the disadvantages of sampling?
It is never going to be EXACT to the population’s statistics. It is only and
ESTIMATION or PREDICTION so there is a possibility of ERROR.
What is saturation point?
In qualitative studies, sampling of the population continues until you have
exhausted all possible new information. This differs person to person due to a whole
host of factors (time, expertise, cost, scope) so it’s a very subjective measure.
What is population/study sample (N)?
It is the population we wish to study.
What is Sample Size (n)?
Sample size is a statistical sample of the studied larger population.
What is Sampling Design/Strategy?
This is the method or process with wish you select members of the sampling frame
to become part of the sample.
What is Sampling Unit or Sampling Element?
Check slide 6 of Lecture 7
What is Sampling Frame***
All possible items/people that can be chosen from the population to be part of the
What are Sample Statistics?
Statistics derived from the sample chosen from the larger population.
What is Population Parameters or Population Mean?
True features and statistics of the population in question.
What are the THREE Principles of SAMPLING? HLTB15 WINTER 2013
Selection of units impacts the difference between sample statistics and population
As sample size INCREASES, the likelihood that the sample is a true estimation of the
population increases as well.
The greater the difference in the variable, the greater the difference between the
sample statistics and the true population mean. (Standard deviation, measure of
spread/ dispersion of sample)* My interpretation.
What are the TWO AIMS of SAMPLING?
Give THREE possible sources of BIAS.
Operational Problems, Sample members refusing to participate
What are the THREE types of Sampling?
What is Random/Probability Sampling Design?
Each element of the sampling frame has an EQUAL and INDEPENDENT chance of
What are the TWO advantages of Random/Probability Sampling Design?
You can GENERALIZE results to the larger population
You can use STATISTICAL tests based on the theory of probability theory. Many
statistical tests have many assumptions, some of them having randomized sampling
What are the THREE types of Random Sampling Design?
Simple Random Sampling
Stratified Random Sampling
What is Simple Random Sampling? (SRS)
You identify the all the elements or sampling units in the population, decide on a
sample size and select that number!
What is Stratified Random Sampling?
We consider this type of sampling in order to reduce the heteregenity in the sample.
For instance, you will g