2. Measures ofAssociation,
Correlation and Regression
Analysis
Presented by:
Hamza Yousaf
M. Phil Education
University of Kotli, Azad Jammu and Kashmir
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by
Hamza
Yousaf
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3. Association
In statistics the word ‘association’ is
about any relationship between two variables, whether
it’s linear or non-linear.
Association is a statistical relationship between two
variables. Two variables may be associated without a
causal relationship.
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Hamza
Yousaf
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4. Measures ofAssociation
In statistics, any of various factors or coefficients used to
quantify a relationship between two or more variables.
Measures of Association in Research
Refers to a wide variety of statistics that quantify the
strength and direction of the relationship between exposure
and outcome variables, enabling comparison between
different groups.
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Hamza
Yousaf
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5. Conti…
Several statistical techniques for determining the
strength of the association among dependent and
independent variables are presented below. The
choice of which technique to use is largely driven by
the level of data being analyzed.
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Yousaf
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6. Level of Data Statistical Technique Test Statistic
Ratio or Interval Pearson’s
Regression/Correlatio
n
R, R2
Ordinal (Rank
Order)
Spearman’s Rank
Order Correlation
Rho ( Rho2
Nominal
(Categorical)
Chi-Square Cramer’s V
Binary (1=Yes,
0=No)
Chi-Square Phi ()
Binary (1=Yes,
0=No)
Logistic Regression Nagelkerke’s Pseudo
R2
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by
Hamza
Yousaf
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7. Correlation
The method of correlation is developed by
FRANCIS GALTON in 1885.
Correlation is a statistical measure that
expresses the extent to which two variables
are linearly related (meaning they change
together at a constant rate).
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Hamza
Yousaf
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8. Conti…
In correlation, the relation between two factors can
fluctuate from absolute to not at all.
Types of Correlation
1. Positive Correlation
2. Negative Correlation
3. Non-Linear Correlation
4. No Correlation
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Hamza
Yousaf
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9. Conti…
• Positive Linear Correlation
If two variables are moving in the same direction, i.e.,
as one increases, another also increases, or as one
decreases, another also decreases.
For example, the gravitational force increases as the
mass of the object increases
Negative Linear Correlation
If the changes in the two variables are in the opposite
direction, i.e., if one variable increases the other
decreases. Height above sea level and temperature.
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Hamza
Yousaf
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10. Conti…
• Non-liner Correlation
Known as curvilinear correlation.
For Example, bakery’s daily output of bread and
number of bakers.
• No Correlation
The absence of any relationship between the two
variables leads to zero or no correlation.
For example, the grades obtained by students in
examinations and their height.
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Hamza
Yousaf
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11. Correlation Estimation
There are different ways of estimating the
correlation between two random variables. Here
we discuss three ways.
• Scatter Diagram
• Pearson’s Correlation Coefficient
• Spearman’s Rank Correlation Coefficient
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Hamza
Yousaf
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14. RegressionAnalysis
• Regression analysis is a set of statistical methods used for
the estimation of relationships between a dependent
variable and one or more independent variables.
• It can be utilized to assess the strength of the relationship
between variables and for modeling the future
relationship between them.
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Hamza
Yousaf
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15. Conti…
• Regression analysis is a way to find trends in data.
For example, you might guess that there’s a connection
between how much you eat and how much you weigh;
regression analysis can help you quantify that equation.
• Prediction about your data
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Hamza
Yousaf
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16. Types of RegressionAnalysis
1. Simple Linear Regression
The relationship between a dependent variable and a
single independent variable is described using a basic
linear regression methodology.
2. Multiple Linear Regression
It is a statistical process that uses multiple explanatory
factors to predict the outcome of a response variable.
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Hamza
Yousaf
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18. Conti…
Polynomial Regression Analysis
It allows you to consider non-linear relations
between variables and reach conclusions that can be
estimated with high accuracy.
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Hamza
Yousaf
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19. Application of RegressionAnalysis
5 applications of regression analysis are following:
1. Forecasting
2. CAPM (Capital Asset Pricing Model)
3. Comparing with Competition
4. Identifying Problems
5. Reliable Source
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Hamza
Yousaf
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