SOSC 3993 May 30, 2013
Lecture 6- Sampling
Why would researchers take a sample?
o Because its hard to take an entire population
o Less time consuming
o Cheaper and convenient
o Selecting a sample for a quantitative sample
Why would you select a sample?
o 2 types of samples
1. Random sampling - able to generalize
2. Convenience sampling- less generalizable
Non- probability sampling
Non – probability sampling
o Causes bias in sampling
Ex: an interview in your family won’t be able to generalize to all of Torontonians.
o Volunteer people, some people volunteer for specific things though.
o Not a waste of time, the information is important either way
Ex: study people at York with anxiety not generalizable but useful
o Interested in getting an in depth information
samples; units of analysis
entire set of study elements ( what you want to study )
Ex: sample population of Torontonians
o Study population ( what you can study)
Ex: study people who commit white collar crimes, everyone` in Canada gives info, except
o Finer distinction
o Describe where you get your info
o Sampling frame
List of all the possible elements from which your sample can be taken.
Applies more to random sampling
o Population parameters
Ex: people in Toronto, but you have no time to study all of them
You take sample of Toronto, which generally represents the entire population of Toronto
Characteristics of your population
Ex: 1500 torontonians to see if who would they vote for, and hope that they would
represent what the general population would vote for.
It’s a fact about the population
Ex: sample and find out what the majority of the age groups are.
o Sampling error
Degree of error given to a sample in a specific time
Reflects the difference of what you fin din your sample and the population parameters.
More random, smaller sampling error
Ex: 50 % women 50 % men, random sampling possible you can get all men but highly