Quantitative- surveys Flashcards
2 important aspects of surveys
- sampling
- structuring the questions
(also response rate)
Probability sampling
- Each person has an equal chance of being chosen to be in the sample
- Used whenever you want to learn something specific about an identifiable group of individuals (generalise back to the population)
- We need a representative sample in order to generalise about the population, otherwise the sample is biased
Random sampling (3 types)
- Simple random sampling
- stratified sampling
- Cluster sampling
Simple random sampling
- effective and practical except:
1. when you want to look at systematic features of the population (eg. gender, old people)
2. when the population is very large
Stratified sampling
Proportions of important subgroups in the population are represented precisely in the sample
suppose we have 5000 students and 4000 are women: we would randomly sample within the women and randomly sample within the men.
you slice you population by a variant like gender
Cluster sampling
A “cluster” is a sampling unit (a required class, a school) within which one samples randomly
Non-probability sampling
Can be used when generalisability is not the goal, but the relationship between two variables is.
2 types:
- convenience sampling
- purposive sampling
Convenience sampling
Requesting volunteers from a group of available people who meet the general requirements of the study (SRPP)
Purposive sampling
Recruiting a specific type of person
Survey methods (3 types)
- interview
- written survey
- phone surveys
Advantages of interview method
- Comprehensive, yields lots of information
- Usually don’t get problems with unclear information or missing data (Good for illiterate population in SA)
Disadvantages of interview method
- people refuse to be interviewed, cant be found, or interviewer refuses to go there
- costs, logistics
- interviewer bias
Written surveys
-Use either open or closed questions
-Often use Likert-like scales
-Can be sent through the post or online or administered in a group setting
(bad for illiterate people)
Phone surveys
- Use random digit dialing (to avoid missing unlisted numbers)
- Do exclude that portion of the population that doesn’t have a phone
- Non-response rate can be high
Evaluating survey research: was the sampling frame bias?
- was everyone included?
- was the response rate high?