"Error in t.test.formula (ttResults <- t.test(airline$favorite_count ~ airline$screen_name) : grouping factor must have exactly 2 levels

My code is ttResults <- t.test(airline$favorite_count ~ airline$screen_name). It's for a data frame I have. The favorites is my numerical var and screen name is my categorical var. I've done the same test with similar code before and it worked.

I'm pretty new to R. I'm not sure how to check how many levels I have or recode to adjust the levels.

https://stackoverflow.com/questions/67326898/error-in-t-test-formula-ttresults-t-testairlinefavorite-count-airlines April 30, 2021 at 09:00AM