Sampling is a research method based on “observations and statistical inferences about a population.” (65)
Three things must be considered:
- The sample population- the group of individuals one selects to study
- The Sampling Frame- the criteria applied to make a selection
- The Sample- “what” or “who” is being observed.
The sampling process encompasses several stages
Step One
Select the Population, it “can be defined as all people or items (unit of analysis) with the characteristics that one wishes to study.” (65) The subject being observed and/or studied can be:
- A person
- Group
- Organization
- Country
- Object
- Or anything else one wishes to observe/study
Step Two
Choose a sampling frame
- Target Population
Sampling Techniques
- Probability
- Simple Random
- Systemic Sampling
- Stratified Sampling
- Cluster sampling
- Matched Pairs Sampling
- Multistage Sampling
- Non- Probability
- Convenience sampling
- Expert Sampling
- Quota Sampling
- Snowball Sampling
Statistical Data Derived from Research
- Response- Answers provided by sampled participants
- Frequency distribution
- Normal distribution- a bell curve distribution of responses. It will produce sample statistics
- Population Parameters- Are unknowable
- Sampling Error- The difference between statistics and population parameters
Validating sample Results
- Confidence Interval
68-95-99 Rule- 68% of the cases in the distribution lie within one standard deviation of the mean value. 95% are within two standard deviations of the mean, and 99% lie within three standard deviations. A sample is considered biased if it falls out this rule.
This was a great summary of the chapter, and I think you did a good job of condensing all of the information. This is one of my favorite methods to use because of the quantitative data aspect. Especially when it comes to analyzing the information using techniques like the confidence interval is really interesting to me. In addition, I was unaware of exactly how many sampling techniques that existed, but really opened my horizon to the flexibility of Sampling.
Renee – Thank you for such a sharp and focused recap of chapter 8! Your summary really help me to focus on the critical takeaways from the text!
As I was reading the chapter, the question arose for me – “how does a researcher know which sampling technique is correct for their research?”. Perhaps it is intuitive with the research topic? I recognize that my default analysis has a tendency to be on the qualitative versus the quantitative methodology and the answer may be obvious to others!
With that said, as I read the last section regarding sample bias, another question emerged for me. If a sample violates the 68-95-98 rule, is it an issue with the sampling frame or the sampling technique? As my research project proposal with most likely not use a sampling method, I’ll tackle the answer to that last question another day!