Question

Explain the types of correlation.

Write short notes on the following:

Three types of correlation

Answer 1

Type	Meaning	Value of correlation coefficient	Example
Positive	Both variables either increase or decrease at the same time.	Between 0.00 and +1.00	Higher the amount of practice, the greater the chances of success. So, practice and success are positively correlated.
Negative	An increase in one variable is associated with a decrease in the other and vice versa.	Between 0.00 to –1.00	The higher the expenses, the lower the amount of savings. So, expenses and the amount of savings are negatively correlated.
Zero	Here, any change in one variable brings no significant change in other variables.	Zero	The level of income is not related to relations with neighbours. So, income level and relation with neighbours are not correlated.

Answer 2

Correlation is a statistical tool used to measure the relationship between two or more variables. If the change in one variable appears to be accompanied by a change in the other variable, the two variables are said to be correlated and this interdependence is called correlation.

The extent of correlation between two variables is measured by the correlation coefficient. A correlation coefficient is always a number between –1.00 to +1.00. The sign (+ or –) of a correlation coefficient indicates the direction of the relationship between the variables.

There are three types of correlation:

1. A positive correlation: When both variables either increase or decrease at the same time, they are said to have a positive correlation between them. In the case of positive correlation, the value of correlation is found between 0.00 and +1.00 For example, The amount of rehearsal and recall score.
2. A negative correlation: When an increase in one variable is associated with a decrease in the other and vice versa, they are said to have a negative correlation between them. In case of a negative correlation, the value of correlation is found between 0.00 to -1.00 For example, amount of exercise and level of body fats.
3. A zero correlation: When any change in one variable brings no significant change in other variable, they are said to have a zero correlation. In the case of zero correlation, the value of correlation coefficient is found to be 0. For example, height and intelligence.