SAMPLING AND SAMPLING METHODS Flashcards
Process of selecting just a small group of cases from out of a large group
Sampling
Why is there a need to sample? When can sampling be a vallid alternative to a census? [4]
- Impracticable to survey entire population
- Budget constraints
- Time constraints
- Results are needed quickly
collective term used to describe the total quantity of things/cases; can consist of certain types of objects, organizations, people or even events
Population
(Characteristic of Population)
All cases are similar
Homogeneous
(Characteristic of Population)
Contain strata or layers
Stratified
(Characteristic of Population)
Contains strata of known proportions
Proportional Stratified
(Characteristic of Population)
Containes distinctive groups
Grouped by type
(Characteristic of Population)
Different groups according to where they are
Grouped by location
estimation of size of the population (applicable only in living individual); capture small number of individuals; tags/marking then release back into population; can be expressed mathematically
Capture-Mark-Recapture (CMR)
CMR Formula
N = (M*C)/R
selected category that will be of interest to the study
Sampling Frame
give the most reliable representation of the whole population; sample from a larger population are chosen using a emthod based on the theory of probability; random selection, equal chance, statistical theory, predict, math the overall population
Probability Sampling
(Type of Probability Sampling)
assigning numbers to the individuals (sample)
Simple Random Sampling
(Type of Probability Sampling)
where a larger population can be divided into smaller groups
classify by sex, age, ethnicity, and similar ways
Stratified Random Sampling
(Type of Probability Sampling)
geographically spread out
city, family, university, etc.
dividing the greater population into various smaller sections
Cluster Random Sampling
