Rank correlation, Applied Statistics

Assignment Help:

Rank Correlation

Sometimes the characteristics whose possible correlation is being investigated, cannot be measured but individuals can only be ranked on the basis of the characteristics to be measured. We then have two sets of ranks available for working out the correlation coefficient. Sometimes the data on one variable may be in the form of ranks while the data on the other variable are in the form of measurements which can be converted into ranks.

Thus, when both the underlying variables are ordinal or when the data are available in the ordinal form irrespective of the type of variable, we use the rank correlation coefficient to find out the extent of relationship between the two variables.

This rank correlation coefficient is also known as Spearman's rank correlation coefficient. Rank correlation is a non-parametric technique for measuring strength of relationship between paired observations of two variables when the data are in a ranked form.

Rank Correlation measures the degree of agreement between the two sets of ranks.

Rank Correlation Coefficient R is

  1153_rank correlation.png

where,   n   =      Number of individuals ranked

             Di   =       Difference in the ranks of the ith individual

             i     =       1, 2, ........ n

 

             Di   =       Difference in the ranks of the ith individual

             i     =       1, 2, ........ n

Example

The ranks of 8 students are given according to their marks in English and History.

Student No.

1

2

3

4

5

6

7

8

English

2

8

1

7

6

4

5

3

History

7

3

2

6

5

8

4

1                                          

 

We want to know whether or not students who are good in English are also good in History. For this the calculations are:

1531_rank correlation1.png

 

Here

1509_rank correlation2.png

= 74 and n = 8

 

R

  706_rank correlation3.png
  = 0.119  

The correlation between the ranks is seen to be low.


Related Discussions:- Rank correlation

Plot diagnostic quantities, The data in the data frame compensation are fro...

The data in the data frame compensation are from Myers (1990), Classical andModern Regression with Applications (Second Edition)," Duxbury. The response y here is executive compens

Regression Analysis, Question 3 25 marks Your employer, Quick Hit Agency ...

Question 3 25 marks Your employer, Quick Hit Agency (QHA), is a debt collections agency. The company specializes in collecting small accounts. QHA does not deal in large accounts

Explain graph theory, For each of the following scenarios, explain how grap...

For each of the following scenarios, explain how graph theory could be used to model the problem described and what a solution to the problem corresponds to in your graph model.

Bernoulli''s theorem, Bernoulli's Theorem If a trial of an experiment c...

Bernoulli's Theorem If a trial of an experiment can result in success  with probability p and failure with probability q (i.e.1-p) the probability of exactly r success in n tri

Harmonic mean, Harmonic Mean  The harmonic mean  also called harmonic  ...

Harmonic Mean  The harmonic mean  also called harmonic  average, in the total numbers of items of variable divided by the sum of r reciprocals of the values of the variable. In

Correlation, Correlation The correlation is commonly used and a useful...

Correlation The correlation is commonly used and a useful statistic used to describe the degree of the relationships between two or more variables. Pearson's correlation refle

Ashland MultiComm Services, Suppose that in the actual survey of 50 prospec...

Suppose that in the actual survey of 50 prospective customers, 6 subscribe to the 3 for all offer, what does this tell you about the previous estimate of the proportion of customer

Sampling, Sampling A  Population  is a collection of all the data point...

Sampling A  Population  is a collection of all the data points being studied. For example, if we are studying the annual incomes of all the people in India, then the population

Define the partial market equilibrium model, Q. The following system of equ...

Q. The following system of equations illustrates the algebraic form of a partial (individual) market equilibrium model, which is a model of price (P) and quantity (Q) determination

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd