Apple Miscalculates WOBBLE Averages in iTunes?

This has been bugging me for a while. Go to Wobble in iTunes, and take a look at the reviews – then add up the total number of stars given by reviewers and then divide by the number of reviews…

In every country our star rating is down by at least one, but for ease of calculation take a look at Canada for Wobble – Wobble has had 119 reviews in the USA (most of them 5 Star) – so that would be a pain to add up… in Canada Wobble has been reviewed just 8 times. (too busy skiing I guess?)

Anyway – Canadians have given us:
6 x 5 Stars
2 x 4 stars

Total 38 – Average (lemme get out my calculator… uh) 4.75 Stars – Wow, thanks Canada, I must visit for a marketing trip next ski season, oops I mean Winter…

EXCEPT Apple show just 3 Stars – Hey! How does that work??Canada 3 star

I know Apple don’t like Wobble, but geez? :-) Or maybe other Apps see the same thing? And before you say it’s a worldwide rating – it isn’t, I checked.

Update – after Grahs comment
(Not sure if this is the answer since there are many ratings with no reviews)

If this average is the result of people leaving ratings after uninstalling the Application then I think the formula to calculate how many people have left a rating when uninstalling is (38+y)/(8+x)=z where 2.75<z<3.25 SO, since that can’t be readily solved this is not a transparent process.

BUT, Let’s assume that X and y are equal – since a 1 star rating is likely, and assume z is exactly 3…. a few lines of scribble shows that 6 ratings of 1 Star is the answer.  In comparison there are just 8 ratings from satisfied customers in Canada. So 6 people who for whatever reason remove the app and give it a bad rating lower the stars from 4.75 to just 3.

If x and y are not equal and the average person removing the app is leaving a 2 star rating, then it means that there must be 12 x 2 star ratings to make an average of 3 stars when combined with the “real” ratings.

This makes the system appear even worse – 12 remove ratings to just 8 ratings from people who like the App enough to keep it AND come back to the App store to review it!!

I suspect that the more installs you get – the more UNinstalls you would probably get as well. This is why free applications – that have no apparent value to the user have lower ratings I guess.

As many people have said before, asking for ratings from people who uninstall the App is asking for skewed results.

average rating is wrong

1 thought on “Apple Miscalculates WOBBLE Averages in iTunes?”

  1. You don’t need to add a review to rate an app – you’re given an option to rate the app if you delete it.

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