1
SIMPLERANDOMSAMPLE
2
SYSTEMATICSAMPLE
3
CLUSTERSAMPLE
4
SECONDARYDATA
5
PROBABILITY
6
STRATIFIED
7
STATISTICS
8
TECHNIQUE
9
ACCURATE
10
UNBIAS
11
CENSUS
12
ERROR
13
BIAS
14
POLL
X
Q
J
K
S
T
R
A
T
I
F
I
E
D
A
A
A
U
T
I
S
O
D
E
T
A
E
A
C
C
U
R
A
T
E
G
T
G
E
A
A
N
S
B
P
C
L
U
S
T
E
R
S
A
M
P
L
E
A
T
W
D
C
E
O
S
P
O
E
E
R
R
O
R
V
S
K
I
A
A
W
I
I
H
W
I
M
A
G
E
K
E
D
S
E
P
I
X
M
D
S
J
T
N
A
L
A
A
E
L
K
T
U
Y
V
W
G
U
E
Y
A
T
S
S
A
C
S
A
H
K
U
I
J
S
G
I
E
C
A
R
I
Q
I
C
B
K
M
O
F
S
P
P
E
T
V
U
J
J
N
A
B
I
T
A
A
C
O
F
U
I
R
R
E
E
I
V
V
A
A
D
N
A
A
U
Z
D
D
U
Z
S
O
U
D
M
X
D
A
O
Z
N
U
I
T
X
I
C
N
C
O
M
B
O
A
A
R
P
Y
P
O
O
G
Z
S
W
Q
T
A
S
H
A
A
N
L
T
K
I
I
K
U
C
G
O
D
A
O
E
R
A
E
S
B
C
A
I
E
Y
Z
Z
T
E
I
Y
O
H
U
C
E
I
Z
B
I
E
M
C
K
B
S
I
T
S
A
O
C
R
E
H
L
B
W
G
L
N
L
S
V
U
O
Z
M
I
A
U
H
O
H
N
P
E
D
J
I
S
N
A
A
U
O
W
D
R
O
F
O
X
R
I
M
V
W
I
T
U
K
M
O
D
M
I
D
U
O
E
I
S
I
Q
I
O
W
I
Y
S
Y
P
A
Q
N
T
O
F
I
M
J
S
E
U
S
P
O
L
L
F
U
L
E
Z
I
V
G
E
C
Y
U
O
O
E
A
A
E
O
R
E
E
E
O
O
I
O
I
O