correlation co -
efficient rs
Mld8UMS the
strength Of a correlation between two sets of paired data [ variable n and
y
)
>
Vs valves between -
1 and I
> -
I [ perfect c- ) correlation I 0 ( no Corre lotion ) -11 ( perfect Ct > correlation )
,
data ( in order ) another group data ( in order )
comparing group
one of to of
• ordinal data
requires ☒
can be converted to ordinal
☒
Date NOT distributed
normally -
It
÷
•
does not need to be a linear relationship
minimum no .
Of paired observation = 5 Moms Moms Biology Biology
best 10-30 Student score rdhk score rank di
Si 57 3
Slept :
there is no
statistically significant correlation between 83 7
NULL measurement 1 and measurement 2 Sz 45 I 37 I 0
53 7- 2 7 41 2 5 2
there is 54 8 8.5
significant correlation between 7- 8
statistically
no no 85 0-5 0
and 53 2 3
correlation
biology scores moms scores .
Ss 56
56 6 3 5 85 8.5 3-5 1
OR
St 86 9 77 6 3
Alternative There 2 Sg 98 8 7
is
Statistically significant correlation 10 10
= 0
5 9 4
Sq 5
-
between biology scores and moms scores .
70
2
Sio 71 6 59 4
n= number of
2
step 2 :
Rs
=
I -
6-2 di individuals in the
'
n
} n
sample
-
↳ with identicle
-
t.rs ≤ 1 scores divide
by no .
of
di subjects
difference in the rank the two
.
of
=
meotsnrements made on an individual
n = 10
Edi 2=68.5
}
Step : rank each set of data
→ In
Biology ,
a
probability of 5% is adopted so
,
as a standard convention
step 4 :
conch / ate rs
→
only chose p = 0.05 Rs =
1-
6 (68-5)
103 -
10
Step 5 :
calculate critical value s
-
r o 585
-
-
If calculated rs is < Vs critical value = ACCEPT NULL HYPOTHESIS If the loiknloted value of Rs > rs critical value
↳ There is NO
significant correction REJECT NULL HYPOTHESIS
[
=
The
probability the correlation is one to chance is greater then 5% likely biological 5 ↳
significant correlation between and
[[
a
y
treason
The probability of the correlation occurred
due choice < 5%
likely correlation due to chance to