bioe demography and sampling

6000 years ago

Earliest demographic activity

john graunt 1662

"Father of demography"
"Natural and Political Observations Made Upon the Bills of Mortality"

POPULATION CENTERED DEMOGRAPHY (19th Century)

Brought about different populations' needs and thus demography was
adjusted to fit the need of certian population

Define Population
Determine sample size
Select Sampling Technique
Create the Sampling Frame

STEP IN EXECUTING SAMPLING

cochran’s

correcting

adjusting

yamane’s

stratified

draw

SAMPLING FORMULA:

probability

non-probability

GENERAL TECHNIQUES IN SAMPLING

probability

- All member of the population has an equal chance to be

simple random

systematic

stratified

cluster

4 TYPE OF PROBABILITY SAMPLING

Simple Random

- The best sampling technique to obtain a representative sample

Systematic

- Every nth element chosen at random and in predetermined succession

Stratified

- Population is divided into smaller group/strata

Cluster

- Population is divided into clusters. Clusters are selected as sample

NON PROBABILITY

- Sampling is intentional and purposeful

Purposive

Convenience

quota

snowball

4 TYPE OF NON PROBABILITY SAMPLING

Purposive

- Samples are selected based on what is required

Convenience

- The nearest and most accessible samples are taken

Quota

- Samples are taken based on a set of predetermined criteria

Snowball

- Sample are referred to by already participating sample