# How to create a Pearson Correlation and others with this data?

#### Joker

##### New Member
Hello everyone..
I am struggling to create a Pearson correlation with this data below: My goal here is very simple, identify correlations between each module and the severity number. (Its related to Defects)
I tried Pearson correlation but did not work out well. Can someone give me a hint of how can I make this into an outstanding analysis? Its for a work meeting...
Thank you very much!

#### Omerikooo

##### New Member
Hello Joker,

Correlation refers to a relationship between two continuous variables. For example, it is possible to look for a correlation between age and height of a group of people.

In your case you have a module variable (which I understand is a nominal variable), and severity which is an ordinal variable. In order to understand the relationship between module and severity you can use chi-square( better option) or t-test (acceptable option).

Chi-square simply tells if your module variable affects the frequency of the severity variable.

T-test would be a better option if your severity variable was not recorded as categories.

#### Joker

##### New Member
Hello Joker,

Correlation refers to a relationship between two continuous variables. For example, it is possible to look for a correlation between age and height of a group of people.

In your case you have a module variable (which I understand is a nominal variable), and severity which is an ordinal variable. In order to understand the relationship between module and severity you can use chi-square( better option) or t-test (acceptable option).

Chi-square simply tells if your module variable affects the frequency of the severity variable.

T-test would be a better option if your severity variable was not recorded as categories.
Hello Joker,

Correlation refers to a relationship between two continuous variables. For example, it is possible to look for a correlation between age and height of a group of people.

In your case you have a module variable (which I understand is a nominal variable), and severity which is an ordinal variable. In order to understand the relationship between module and severity you can use chi-square( better option) or t-test (acceptable option).

Chi-square simply tells if your module variable affects the frequency of the severity variable.

T-test would be a better option if your severity variable was not recorded as categories.
Thanks for the reply!

Do the variables need to be "Double" to make the correlation work? Because the Module column is a string..

#### Omerikooo

##### New Member
Thanks for the reply!

Do the variables need to be "Double" to make the correlation work? Because the Module column is a string..
String is probably fine for your purpose but it would be good to know which software you are using.

It is not statistically sound to call this a correlation. You can refer to wikipedia: "Pearson's chi-squared test is used to determine whether there is a statistically significant difference between the expected frequencies and the observed frequencies in one or more categories of a contingency table."

#### Joker

##### New Member
String is probably fine for your purpose but it would be good to know which software you are using.

It is not statistically sound to call this a correlation. You can refer to wikipedia: "Pearson's chi-squared test is used to determine whether there is a statistically significant difference between the expected frequencies and the observed frequencies in one or more categories of a contingency table."
String is probably fine for your purpose but it would be good to know which software you are using.

It is not statistically sound to call this a correlation. You can refer to wikipedia: "Pearson's chi-squared test is used to determine whether there is a statistically significant difference between the expected frequencies and the observed frequencies in one or more categories of a contingency table."
Thank you so much!