2(ii) Spearman’s RHO
A-Level Psychology, Research Methods:
“How to do the statistical tests”
Spearman’s Rank Order Correlation Coefficient
What is it and when is it used?
Spearman’s Rho is used when we are trying to find a ____________________ between two
____ _____________________. The two sets of data have to be _______________. The level
of measurement also has to produce ______________data.
Examples
Is there a relationship between the cost of chocolate and the taste?
Hypotehsise!
Experimental:
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Null:
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Probability level I am willing to accept is_____
Table to show___________________________ Graph to show______________________________________
__________________________________________ ___________________________________________________
(Complete with scores)
What do your descriptive results tell you?
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
(If we didn’t have a correlation, let’s pretend we did for the purposes of the next bit!)
Now for the inferential stats!

Complete all activities up to and including the
NULL HYPOTHESIS on your worksheet.
Correlation
Variable
Positive
Correlation
Negative
Correlation
Zero
Correlatio
n
An analysis of the
strength of a
relationship
between two
variables
When there is
no
relationship
between the
variables
A factor of thing
that can
change-it varies.
March 8, 2019
Title: Research Methods: Correlations AND
hypotheses
As one variable
increases or
decreases, the
other does the
same
Spearman’s Rank Order Correlation Coefficient
What is it and when is it used?
Spearman’s Rho is used when we are trying to find a ____________________ between two
____ _____________________. The two sets of data have to be _______________. The level
of measurement also has to produce ______________data.
Examples
Is there a relationship between the cost of chocolate and the taste?
Hypotehsise!
Experimental:
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Null:
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Probability level I am willing to accept is_____
Table to show___________________________ Graph to show______________________________________
__________________________________________ ___________________________________________________
(Complete with scores)
What do your descriptive results tell you?
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
(If we didn’t have a correlation, let’s pretend we did for the purposes of the next bit!)
Now for the inferential stats!

Answers
Correlation
Variable
Positive
Correlation
Zero
Correlatio
n
An analysis of the
strength of a
relationship
between two
variables
When there is no
relationship
between the
variables
A factor of
thing that
can change-
it varies.
.
March 8, 2019
As one variable
increases or
decreases, the
other does the
same

Apply it!
March 8, 2019

Some basic information:
 A statistical test performed to see if
the calculated correlation coefficient
(rs figure) is significant
 The coefficient is calculated from
related data (usually two measures
about the same person) and can be on
a scale from +1 through to -1.
 Where +1 is a perfect positive
correlation and -1 is a perfect negative
correlation.

Spearman’s RHO
Conditions for use:
 When co-variables are collected for a
correlation study
 When scale data has been converted
into ordinal data (ranked)
 Not suitable to use with ‘tied ranks’
 Correlations are always related, pairs
of data

Remember-for correlations we do not
have IV and DV
Co-variables
What are the 2 co-variables for
this study;
Researchers wanted to investigate
how the frequency of illness
affected an employees
professional development in the
workplace.
Co-variable 1: illness (absenteeism)
Co-Variable 2: professional development (salary
increases, promotions, appraisals)March 8, 2019

chocolate!chocolate!
Is there a correlation between theIs there a correlation between the
price of chocolate and how tastyprice of chocolate and how tasty
it is?it is?
What could weWhat could we predictpredict about theabout the
relationship between the cost ofrelationship between the cost of
chocolate and it’s taste?chocolate and it’s taste?
March 8, 2019
There’s only one way to find out!!!!!

What would you need to control?
Blind test, type of chocolate, amount eaten
How/what would you operationalise
the co-variables?
Taste (sweetness? Texture?)score /5 and weight
Ethical Considerations?
Allergies, freedom to withdraw

Name: Taste score
out of 5
(1 not tasty-
5 delicious)
choc1
choc 2
choc 3
choc 4
choc 5
March 8, 2019
Name: Taste score
out of 5
(1 not tasty-
5 delicious)
choc 1
choc 2
choc 3
choc 4
choc 5
Name: Taste score
out of 5
(1 not tasty-
5 delicious)
choc 1
choc 2
choc 3
choc 4
choc 5
Name: Taste score
out of 5
(1 not tasty-
5 delicious)
choc 1
choc 2
choc 3
choc 4
choc 5

Collate the class
scores...
Calculate MEAN taste scores for each
choc!
March 8, 2019

March 8, 2019
The actual order of price (PER 100g)
choc 1 choc 2 choc 3 choc 4 choc 5
5
1
4
3
2
Order
of
eating!
#chocolate#chocolate Price in bhtPrice in bht
per 100gper 100g
Mean tasteMean taste
scorescore
11 40 2.4
22 70 2
33 89 3.4
44 110 3.8
55 139 3.5

Some data collected in a correlation study
Hypothesis (simplified): Negative correlation
between happiness and time spent on internet
socializing
#chocolate#chocolate Price in bhtPrice in bht
per 100gper 100g
Mean tasteMean taste
scorescore
11 40 2.4
22 70 2
33 89 3.4
44 110 3.8
55 139 3.5

March 8, 2019
Chocolate Taste score
1 2.4 Correlation Coefficient = 0.815139
2 2
3 3.4
4 3.8
5 3.5
0
0.5
1
1.5
2
2.5
3
3.5
4
0 1 2 3 4 5 6
TasteScore/5
Biscuit value
A scattergraph to illustrate the relationship between
chocolate price (per gram) and taste score out of 5
#chocolate#chocolate Price perPrice per
100g100g
Mean tasteMean taste
scorescore
11 40bht 2.4
22 70bht 2
33 89 3.4
44 110 3.8
55 139 3.5

Use half of your sheet to plot a scatterUse half of your sheet to plot a scatter
graph to show the results.....graph to show the results.....
Include....Include....
• A titleA title
• Labels for the axesLabels for the axes
• A written paragraph explainingA written paragraph explaining
your results. So far, haveyour results. So far, have
you met your hypothesis?you met your hypothesis?
March 8, 2019

Here comes the science
bit….

First calculate the sum of
differences squared (⅀d²)
## a) Pricea) Price
per 100gper 100g
b) Mean Tasteb) Mean Taste
scorescore
c) Rank forc) Rank for
column (a)column (a)
d) Rank ford) Rank for
column (b)column (b)
Diff = dDiff = d
(ra-rb)(ra-rb)
d²d²
1 40 2.4
2 70 2
3 89 3.4
4 110 3.8
5 139 3.5
⅀⅀ d²d²

Now complete the formula
Where n = 6 and ⅀d² = 68
So
r₂ = 1- (6 x 68) = 1-1.94 =
-0.943
6(36-1)
r₂ = -0.943
Coeficcient =
0.8151

Critical Value Table
The calculated r : ________ is than₂
______ so we can _______ the
null and _________ our directional
hypothesis at 5% (0.05)
One tailed
0.05 0.025
n 0.10 0.05 0.02
5 0.900 1.000 1.000
Two tailed
r₂ must be equal to or greater
than the critical value

Now over to you