Internet Movie Database (IMDb) on Monday, 14 March, changed the ratings for a Hindi film – The Kashmir Files – after detecting ‘unusual voting activity’ on the movie’s review page. While it was first rated a perfect 10, the rating was changed to 8.3/10, based on over 2.3 lakh votes.
The director of the film Vivek Agnihotri objected to the revision, terming it as "unethical."
How does IMDb rate files? Is this revision unusual? Here's all you need to know.
What is IMDb?
The platform is a database of films, from across the world, with each of the films rated out of 10. This is based on the votes registered by the users of the platform.
Who can rate the films?
Only those who are the registered users of the platform can rate the films. Notably, the ratings are not registered by movie critics.
However, IMDb's Top 250 films are rated differently. These films are selected on the basis of votes of 'regular IMDb voters.' However, the platform has not revealed what makes someone a 'regular.'
How is the final rating derived?
The IMDb, on its website, explains that it takes all individual ratings cast by IMDb registered users and uses them to calculate a single rating.
However, they don't use arithmetic mean, that is, the sum of all votes divided by the number of votes. This is done by a method called weighted average.
"We don't use the arithmetic mean (i.e. the sum of all votes divided by the number of votes), although we do display the mean and average votes on the votes breakdown page; instead the rating displayed on a title's page is a weighted average," the platform has explained.
What is weighted average?
While IMDb accepts and considers all votes received by users, not all votes have the same "impact" (or 'weight') on the final points.
"When unusual voting activity is detected, a different weighting calculation may be applied in order to preserve the reliability of our system. To ensure our rating mechanism remains effective, we don't disclose the exact method used to generate the rating," the website explained.
This was cited as the reason for changing the rating on IMDb.
People may be voting to either increase or decrease the rating for propaganda. How does IMDb counter this?
The IMDb claims to have several safeguards in place to automatically detect and defeat any type of ballot stuffing.
"Even though we count and display all unaltered votes in the rating breakdown, we apply several countermeasures against all attempts to skew the rating and the weighted rating you see displayed on the site already takes all of the above into consideration," the website says.
Where can I see a detailed breakdown of votes?
To view detailed votes breakdown, you can click the number of votes located directly below the average IMDb user rating.
Is there a filter where only those people who have watched the film rate it?
No, there is no such filter on IMDb.
(At The Quint, we are answerable only to our audience. Play an active role in shaping our journalism by becoming a member. Because the truth is worth it.)