This presentation is about Pearson's product moment correlation

1. CORRELATION

2. Meaning and definition of Correlation
•Francis Galton carried out early work on
correlation
•His colleagues, Karl Pearson, developed a
method of calculating correlation
coefficients for parametric data

3. Definition of Correlation
•Correlation can be defined as ‘the degree of
relationship between two variables’.
(or)
•Correlation analysis attempts to determine the
degree of relationship between variables.
(or)
•Correlation means that between two series or group
of data there exists some causal connection.

4. •Pearson's Product Moment Correlation Coefficient
•Symbol “r” or PPMCC or PCC
•Pearson “r”
•Relationship existing between pairs of measure
•Usually each pair of measures is obtained from the same individual.

5. •The range of possible magnitude of
correlation extends from +1.00 to -1.00
•Correlation value is basically a single
score which indicates the relationship
between two sets of data.

6. •The sign does not have mathematical meaning but,
rather it indicates the direction of the correlation.

7. r RELATIONSHIP
-1 Perfectly negatively
correlated
< -0.6 Highly negatively correlated
0 No correlation
> +0.6 Highly positively correlated
+1 Perfectly positively
correlated

8. •To study the relationship between the 100
metres performance and physical variables.
•Swimming performance & strength is
used in prediction.
•Correlation analysis is the statistical tool
that we can use to describe the degree to
which one variable is related to another.

9. Uses of Correlation in Physical Education
•To measure the degree of relationship between two
variables, correlation is used.
•Correlation is extensively used in Physical Education
research.
•In research, to check whether there is significant relationship
between two factors is there or not, this technique is used.
•Inter-relationship between various factors can be assessed
by using correlation technique.
•Correlation is first step involved in advance statistics such as
factors analysis, multiple regressions and so on.

10. The computation of Pearson's Product
Moment Correlation from ungrouped
data can be done in two ways namely
1. Raw Score methods
2. Deviation methods

11. I. Raw Score methods
To compute co-efficient of correlation
from raw scores of small sample
(ungrouped data), the following formula is
used

12. II. Deviation methods
‘Moment’ is the sum of the deviation of scores
from their mean raised to sum of power & divided by
N. Product movement when pairs of deviations in X
and Y are multiplied, summed and divided by N. In
correlation, X and Y are multiplied. Summed and
divided by N. In correlation, X and Y have the same
meaning except X represents one of the variables and
Y represents the other. Thus x=X-Mx and y=Y-My.

13. Correlation between performance in 100 mts and
30 mtsS.N 100-mts in
secs
30-mts in
secs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
13.20
13.20
14.13
13.01
14.09
15.49
14.82
14.45
14.90
17.72
14.57
15.54
16.65
14.56
15.16
15.15
14.39
13.01
15.51
14.36
4.20
4.50
5.00
4.40
5.12
5.60
5.00
4.60
5.10
5.21
4.80
5.22
5.26
4.60
4.61
4.99
4.66
4.33
5.01
4.75
The correlation coefficient r =
0.743
Highly positively
correlated

14. Thank you for your attention!