Hey, can anyone help to explain the Chi-square test? I'm stuck on how you're meant to work out the 'expected' values. Thank you!
Chi-Squared Test? Watch
- Thread Starter
- 25-05-2016 20:04
- 25-05-2016 20:07
the expected value is worked out by row total multiplied by column total, the divided by the grand total. You do this for each value.
- 25-05-2016 22:04
Here's an explanation I wrote out for somebody earlier - Hopefully it helps:
The Chi-squared test is used when data is categoric and it is used to calculate the difference between the OBSERVED and EXPECTED details. It relates the number of individuals in particular categories and the calculation creates something called a "chi squared" value. The HIGHER the "chi squared" value calculated, the GREATER the difference between the observed and the expected results. Again, degrees of freedom can be calculated here (n-1) with n being the number of categories. Again, there will be a reference table and IF THE CHI SQUARED VALUE IS GREATER THAN THE CRITICAL VALUE then you REJECT the null hypothesis which shows that the probability that the results are due to chance is 5% or less AND THEREFORE this means THERE IS A CORRELATION BETWEEN THE DATA.