BIOS 664
Cluster Sampling:
One and Two Stage Sampling
(Unequal-Sized Clusters)
1
Presentation #5
Lecture Notes: Section 7
2
A Population with Unequal-Sized Clusters
Population
(x,y)11
(x,y)12
(x,y)21
(x,y)22
First Cluster
(x,y)23
(x,y)41
Second Cluster
(x
Notes for Presentation File # 6
Slide 27
Procedure to select c 2 independent systematic samples:
1. Choose (with replacement) c independent random starts (numbers), R1 , . . . , Rc , between 1 and ck
2. For each random start, choose every (ck)th element i
BIOS 664
Systematic Sampling
1
Presentation #6
Lecture Notes: Sections 8 and 7.4.8
2
Systematic Sampling of
Individual Population Members
A method of equal probability list sampling
Population members in a list are chosen by
applying an interval of consta
BIOS 664
Developing a Sample Design
1
Presentation #7
2
Some General Rules
(1) Talk in language the client can understand.
(2) Be honest with the client.
(3) Consider all sources of survey error.
3
Some General Rules
(4) Find a scientifically sound yet pr
BIOS 664
STRATIFIED SAMPLING
1
Presentation #3
Lecture Notes: Section 5
2
What is Sampling Stratification?
Process
of dividing set of units to be
sampled into subgroups called strata;
Each
unit is assigned to only one stratum
3
What is Sampling Stratifi
BIOS 664
SIMPLE RANDOM
SAMPLING
1
Presentation #2
Lecture Notes: Section 4
2
Sampling Theory
Accounts for the statistical effects of
inference to a finite population from a
sample
Effects of nonsampling sources of statistical
error NOT considered at this
Variance Estimation: Paired Selection Model (Odd n0 )
Select one of the elements in your sample and include it again in your sample.
Example sample: S1 = cfw_1, 2, 3 randomly select one of the 3 elements in S1 and include it
again in your new sample. For
BIOS 664
Sample Survey Methodology
1
Presentation File #1
Lecture Notes: Sections 1 - 2
Foundations
BIOS 664 - Introduction to Sample Survey Methods
Definition of a "Survey"
A method of collecting information about a human
population in which direct (or i
BIOS 664
Cluster Sampling:
One and Two Stages
(With Equal-Size Clusters)
1
Presentation #4
Lecture Notes: Section 6
2
Cluster Sampling vs. SRS Sampling
Discussed Up Until Now
Notes:
SRS assumes that the only sampling units are
members of the population t
BIOS 664
Determining Sample Size
1
Presentation Notes #8
Lecture Notes: Section 9
2
Preliminaries
Sample size => number of respondents
Determining sample size requires some prior
thought about sample design and analysis goals
Even if sample size is determ