This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Chi squared

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

The chi squared test is used to compare characteristics of more than two groups (t test would be an appropriate test for 2 characteristics). Using the tables of chi squared will gives the probability of features being due to chance.

The Technique:

  • deal in numbers, not percentages or proportions
  • produce an expected result - total up the results and divide by the number of results
  • Chi squared is equal to the sum of the values of:

 

( Observed number - Expected number) squared

_____________________________________________

expected number

 

(Squaring copes with the problem of negative results).

In the tables need then to allow for degrees of freedom (see degrees of freedom)


Related pages

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page