Transforming Scores
• Changing the scale of
the data in some way.
• Change each score.
• converting cm. to inches
• comparing values on
different scales (e.g., height
and weight)
• percentiles
Percentiles:
converting data into the % of
people at or below a particular
level.
Example:
Class A: score of 80
Class B: score of 55
Class A
98
1
96
2
88
2
85
3
82
2
80
2
76
3
72
3
70
2
Class B:
60
1
55
2
54
2
51
4
48
3
40
5
37
3
 cf 
percentile   100
 n 
Class A
cf
98
1
96
2
88
2
85
3
82
2
80
2
76
3
72
3
5
70
2
2
Class A
cf
98
1
96
2
88
2
85
3
82
2
80
2
10
76
3
8
72
3
5
70
2
2
Class A
cf
98
1
20
96
2
19
88
2
17
85
3
15
82
2
12
80
2
10
76
3
8
72
3
5
70
2
2
 10 
percentile   100
 20 
percentile  .5100
%  50%
Class B:
cf
60
1
55
2
54
2
51
4
48
3
40
5
8
37
3
3
Class B:
cf
60
1
55
2
19
54
2
17
51
4
15
48
3
11
40
5
8
37
3
3
Class B:
cf
60
1
20
55
2
19
54
2
17
51
4
15
48
3
11
40
5
8
37
3
3
 19 
percentile   100
 20 
%  95%
Z score:
transforms raw data into
distance from the mean in
units of standard deviation
xx
z
s
Your score was 80 in a class
with a mean of 79 and a
standard deviation of 4.
80  79
z
4