Why sample?
All possible units of analysis
Population
If the researcher wants to ensure representativeness of their sample (to the population), they need to know a cases likelihood of inclusion or exclusion in the sample. To do so, the researcher must rely on the tenets of...
Probability theory
A technique where each person surveyed/interviewed is asked to suggest additional people to be interviewed/surveyed
Snowball sampling
Say you wanted to learn about life as a gang member, but you are not engaged in that life. To learn more, you select someone who is deep in the gang life, who can tell you about it, tell you what they know, and maybe even introduce you others. This person is called...
an informant
We want the findings from our sample to be similar to what we would expect to find in the population. This concept is called...
Generalizability; or inference
This category of sampling can be used for engaging in qualitative research, but is necessary for engaging in quantitative research
Probability sampling
To ensure representativeness, a researcher must engage in random sampling of all units in a population. However, to do so, they must have a list of all units in a population. This list is called...
Sampling frame
Say you wanted to learn about life as a gang member, but you are not engaged in that life. You want to meet with a current gang member in order to build a personal relationship with them, develop rapport, and build trust so that they feel comfortable introducing you to the group. This process is called...
Gaining entrée
A category of techniques used to select units based on the convenience to the researcher
Non-probability sampling
The notion that sample has the same (or similar) distribution of characteristics as the population from which it was selected
Representativeness
A technique where a specific number of people are selected based on predetermined characteristics (i.e. race, class, gender, etc.). Sometimes this may fit the distributions of those characteristics in the population.
Quota sampling
Say you wanted to hang out outside the student union to collect survey responses from people passing by... you would be employing which technique?
available subjects/convenience sampling
Instead of collecting data from the population, we collect a sample because...
too time consuming to collect population data; too expensive to collect population data; and the population changes over time
A sample is representative of the population if all cases in the population have __________ chance of being selected/included in the sample.
Equal/an equal
A technique where the researcher orders their list by specific groups (i.e. race, class, gender), and conducts systematic sampling on that ordered list
Stratified sampling
Say you wanted to survey a random sample of undergraduate students at randomly selected universities in the CSU system. The population would be...
all undergraduate students enrolled at a CSU