Monday, 2 March 2015

Amazon Vine and helpful votes.

I am a reviewer for Amazon Vine and I also review outside the Vine program. Since joining Vine I have seen my helpful review percentage fall and I have dropped out of the Top 1000 reviewers. So I thought I would check if there is a statistical difference between helpful review percentage for vine items and non-Vine items. So I did a simple chi-squared test.

The Chi-square statistic, P value and statement of significance appear beneath the table. Blue means you're dealing with dependent variables; red, independent.
 positivenegativeMarginal Row Totals
vine176   (195.58)   [1.96]52   (32.42)   [11.82]228
non-vine777   (757.42)   [0.51]106   (125.58)   [3.05]883
Marginal Column Totals9531581111    (Grand Total)

The Chi-square statistic is 17.3343. The P value is 3.1E-05. This result is significant at p < 0.05.

That is a very significant difference. There is quite a lot of bias because I have many more non-Vine reviews that have been there for much longer than the Vine reviews and my most helpful review is a non-Vine review but this does still support what a lot of Vine members say that some people systematically go around clicking on the unhelpful review button for anything Vine reviews.

No comments: