APPENDIX 2.1.A. SIMPLE RANDOM SAMPLING
A procedure for selecting n units out of the N possible units so that all possible samples have an
equal chance of being selected
Process:
1. Number the units of the target population from 1 to N
2. Randomly select n units of the target population
These n units comprise the simple random sample
Example
Objective: Determine the average dissolved oxygen concentration (over an annual period) in the
releases from a flood control project.
Target population: 365 days
Sample size: 52
Simple random sample: Select 52 random numbers between 1 and 365
Random sampling assures the independence of the observations