1. Raymond Martin rmartin@utech.edu.jm

3. Lecture 7 – Sampling Data are collected to represent a population or study area. –A census is complete enumeration of the population while –sampling uses part of the population to make conclusions about the entire population

4. Lecture 7 – Sampling Cont’d

6. Lecture 7 – Sampling Two types of sampling: –probability or random – non-probability

7. Lecture 7 – Sampling Probability sampling: –no bias; equal probability of subjects being selected – sample frame required - list of study subjects or picture/aerial photograph from which sample selected – maps or aerial photographs may be used.

8. Lecture 7 – Sampling Probability sampling: –simple random – systematic – stratified – cluster