# Is Pearson's correlation the best method to compare strength of relationship between two Likert items across groups?

My dataset comprises of 400 respondents. They are shoppers from different sociodemographic backgrounds.

I asked each of them (among other things) how likely or unlikely they are to purchased ice-cream. Similarly, I asked them how likely or unlikely they are to purchase yogurt. They responded on a five point Likert scale.

I am doing a correlation between ice cream purchase and yogurt purchase by gender. So I have r=.8296 for females and r=.7784 for males. Both are significant at p<0.05.

I have then compared the two corrleation coefficients to determine if there is a difference between purchase by male vs. female. I have used one of the online calculators that can compare the coefficients (The calculator is from a reliable source.). The result is not significant.

Is this the right way to test the three relationships? (i.e. male, female, and male-female)

I have asked this question because someone pointed out that using correlation coefficients to assess relationships in this way is at best a weak approach and at worst it is wrong and misleading. I was told to consider more conventional analyses.

I am not statistically trained (I know that is no excuse) and I have to present my findings to an audience who is not very statistically orientated, so I used Pearsons corrleation (which appears quite straight forward to me).

• (-1) This question has been asked so many times in so many ways. It would have been preferable to tack on a concise followup comment to the last thread dealing with this question. Sep 16, 2011 at 14:50
• Tell us this: how would a finding of a significant difference in a correlation affect the recommendations you make? Take the specific example you gave. What if an important person in the audience says, "So what if the difference is significant? What does r=0.83 for females and r=0.78 for males tell me about how I should be marketing my products?" I would like to suggest you first consider what these correlations mean to the audience and only then worry about whether the meaningful differences are truly significant.
– whuber
Sep 16, 2011 at 15:02
• @rolando The -1 is unfair, because Adhesh is asking this question specifically to put an end to the repetitive series of correlation-based questions. See comments at stats.stackexchange.com/questions/15598/… .
– whuber
Sep 16, 2011 at 15:04
• I see--whuber's advice and mine were going at cross purposes. Sep 16, 2011 at 18:11
• See this existing question regarding using Pearson correlation on Likert items: stats.stackexchange.com/questions/8956/… Sep 21, 2011 at 0:12