My expected and observed tables look pretty similar, so I wouldn't have expected to receive a p value of 0.0. I guess one potential problem could be that a few of my expected and received numbers are less than 5. Some are even less than 1.

Could this be causing the 0.0 p value, and if not, what else should I be looking for?

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  • $\begingroup$ What are the sizes of the residuals? Is the p-value truly 0 or are you quoting it rounded to the nearest 0.1? Are you confident you are running the calculation correctly? (For instance, do you get precisely the right result when you perform the same calculation on a dataset with a published answer?) $\endgroup$ – whuber Jul 14 '17 at 19:31
  • $\begingroup$ The p-value is truly 0.0000000000 for some of my categorical variables (not all). I performed the same calculation on a dataset with a published answer and got precisely the correct result. $\endgroup$ – tonychen Jul 14 '17 at 20:47
  • $\begingroup$ Could you 1. fix the spelling in your title, and 2. show a table of observed and expected (unless you have hundreds of cells ... but even that information would be potentially relevant) $\endgroup$ – Glen_b Jul 15 '17 at 0:41
  • $\begingroup$ Here is a table of the observed and expected values: imgur.com/a/T9B2z $\endgroup$ – tonychen Jul 16 '17 at 19:34
  • $\begingroup$ Something I found on the internet... 'Use of the chi-square tests is inappropriate if any expected frequency is below 1 or if the expected frequency is less than 5 in more than 20% of your cells.' So I think I have a problem since I do have expected frequencies less than 1... IDK if I can increase my dataset to fix this, any suggestions? Like, yeah the accuracy is lower because of this problem that I have, but how much does this problem affect the accuracy? $\endgroup$ – tonychen Jul 17 '17 at 2:21

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