Metho Lecture 7 (Sampling & Data collection) Flashcards
What is Probability Sampling?
- typically in quantitative research
- population: the collection of all units of a specified type in a region at a point/period of time
- sampling frame: boundaries of sampling units
- sample: segment of the sampling frame
decreasing order of size: population, sampling frame, sample
(e.g. All Dutch people, all dutch included in phone book, every 10,000th entry)
Types of probability sampling
Simple random sample (one person is pointed at in a crowd with eyes closed) Systematic sample (every 5th person) - stratified random sample - multi-stage cluster sample
respondent
Befragter
Stratified random sampling
- ensures that you include enough respondents from different groups
- divide population into mutually exclusive groups
- goal: increase precision
multi-stage cluster sampling
population, cluster one, random sample –> sample one
population, cluster two, random sample –> sample two
…
difference to stratified sampling: cost reduction, not precision
What are probability samples used for?
- enables generalization of results beyond sample, to population
- make statements about average (or mean) scores in population
What is Non-probability sampling?
- typically in qualitative research
Non-probability sampling:
Quota sampling:
- Quota sampling: ensures that you include enough respondents from different groups, with nonrandom selection of elements
- convenience sampling: sample easily available to the researcher
Non-probability sampling: positive/judgmental sampling:
select those cases that help you best answer your research question, very small sample
Non-probability sampling: snowball sampling:
asking selected respondents to nominate or appoint subsequent respondents
Non-probability sampling:
self-selection sampling:
publicise your need for participants and collect data based on who responds
Types of interviews
- structured/standardized
- semi-structured
- unstructured/in-depth
- structured/standardized interview
- survey
- deductive
- closed ended answers
- structured operationalization (Messbarmachung)
- semi-structured interview
- very common
- theory-driven, but leaves room for undiscovered elements (inductive)
- semi-structured operationalization (Messbarmachung)
- unstructured/in-depth interview
- theory building
- narrative interview
- no operationalization (Messbarmachung)