IMDb Votes/Ratings Top Frequently Asked Questions
This page includes answers to the most common feedback, complaints and frequently asked questions about IMDb.com's voting system and user ratings. Please read these notes carefully before contacting us.
- Who can vote on movies and TV shows?
IMDb registered users can cast a vote (from 1 to 10) on every released title in the database. Users can vote as many times as they want but every vote will overwrite the previous one so it is one vote per title per user. - How do I see my past votes? Can I change or delete a vote if I changed my mind?
You can view your voting history by going to http://imdb.com/list/ratings. To delete a vote, simply go to the film or show page on the site hover over the interactive star bar, and click on the red "x" icon.Please note that vote totals are not recalculated instantly so it may take 24 hours for your change to be reflected on the title's rating page.
Also remember that if you simply want to change your vote on an individual film or show instead of deleting it, you can vote again. Subsequent votes always replace the existing one. - How do you calculate the vote displayed on a film or show page?
We take all the individual votes cast by IMDb registered users and use them to calculate a single rating. We don't use the arithmetic mean of the votes (although we do display the mean and average votes on the votes breakdown) -- the rating displayed on a film's page is a weighted average. To display the detailed votes breakdown, click on the 'More' link located below the existing user rating. For an example, see here. - What does 'weighted average' mean?
A weighted average means that some votes have more weight than others in our calculations. If you want more information, see this detailed explanation. - The average vote on film or show XYZ is wrong. Do you realize your math is way off?
The rating is correct -- please remember that the rating is weighted. We do not simply calculate the average by adding up all the votes and dividing the total by the number of votes. Please refer to our weighed average for more information. - But I made my own calculations and the rating for movie or show XYZ should be 7.7, not 4.3! What gives?
We do not disclose our rating/weighting scheme so you can't possibly know what the weighted rating should be. Please remember that the rating is weighted -- it's not the arithmetic mean value of the votes. To prevent abuse and minimize attempts to stuff the ballot or otherwise influence the integrity of the voting system, we do not, under any circumstances, reveal any details about how weighted ratings are calculated other than what is already documented. However please rest assured that there is no bias involved. The same criteria are uniformly used to calculate all the ratings for all the movies in the database. - This is unfair! That film / show has received awards, great reviews, commendations and deserves a much higher vote! Can you change it to reflect this?
Our voting system is meant to offer a representation of what our users think of a film or show based on their votes. We do not collect or consider published reviews or critics' ratings or any other external factor: only votes cast by IMDb users are counted.
We do not delete or alter individual votes and we do not adjust the results of our automated weighted rating for any individual movie / TV show. If the rating is lower than expected, it simply means that IMDb users who voted have a different opinion than those reviewers who liked it. - But film / show XYZ was never shown outside the US and yet you show a dozen votes from non-US users. Clearly they are fake votes and they should be deleted?
Location information is based on the locale the user provided when he registered with the site, not when he voted. An example: if a Swiss national registers with IMDb and enters his location as Switzerland, then visits the United States and sees a film at a festival while in the US and then votes for it, the vote will be recorded as coming from a non-US user. - I know for a fact that the people who voted on a certain film cannot possibly have seen it! They have a grudge against the filmmakers. Will you delete/disregard their votes?
Our standard for allowing users to vote on a film is very simple: the film must have been released and/or screened to the public at least once. If a film meets this requirement, we let our registered users vote on it.
While there is no foolproof way to verify that users have actually seen the film that they are voting for, or that the vote that they are casting is what they really think about it, we depend on and expect our users to be truthful and only vote on those films that they have personally seen.
We are aware that there are people who vote for the sole purpose of trying to lower the rating for a film (this happens both ways -- there are just as many people who try to inflate a vote). As previously stated, we have several safeguards in place to automatically detect and defeat this 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 rating on my film or show has suddenly dropped from 9 to 2. Something must be off. Is your system broken?
It's not uncommon for initial ratings to start high and then go down after a brief period of time (for more details, see here). Films or shows with a relatively low total number of votes (less than a hundred) are particularly susceptible to substantial changes in the weighted rating. When a title only has a few votes, it doesn't take a lot for the rating to change. - But how do you explain that the rating on the film / show has changed even though the total number of votes did not?
There are several explanations for this. First, users are allowed to delete their vote. So if the rating changes even when the total doesn't, it usually means that some people have deleted their vote while the same number of people have added theirs.
Another common explanation is that the weight assigned to votes cast by certain users has changed, so the weighted rating will be affected even when no new votes have been cast.
Finally, please remember that our voting system is always being improved and the formulas used to calculate ratings (and defeat ballot stuffing) are tweaked regularly -- weighted ratings are computed daily, so when the formula is changed the ratings will also change even without new votes. - Why do certain films have a note saying "Awaiting 5 votes" instead of displaying a rating?
We don't display a rating unless a film has received at least 5 votes. And we do not display votes for a film before it has actually been screened/released. In some rare cases we may have an incorrect release date attached to a title, which means that the film may be already available but still be marked as unreleased and therefore missing a rating. If this is the case, you can submit a correction to the film's release date (if applicable) or contact us with detail of the film's release date/status and we'll look into it. - What is the "IMDb Staff" category displayed in some vote breakdowns?
Those are votes cast by IMDb staff members. As explained here they do not carry a special weight on the rating. - Where are the IMDb Top 250 Top Rated Movies and Top 250 Top Rated TV Shows lists?
The Top 250 Top Rated Movies chart is located at http://www.imdb.com/top_250_films. The Top 250 Top Rated TV Shows chart is located at http://www.imdb.com/chart/toptv. - According to its rating, film or show XYZ should be in the Top 250 Rated list but it's missing. Why?
As documented on the Top 250 Chart page, only votes from regular IMDb voters are considered when generating the Top 250 Rated out of the full voting database. This explains any difference between the vote averages reported in the Top 250 Rated Charts and those on the individual movie pages, as well as why movies, whose averages make them seem as though they should appear on the list, do not.
To maintain the effectiveness of the Top 250 Rated Charts, we deliberately do not and will not disclose the criteria used for a person to be counted as a regular voter. - How do you calculate the rank of movies and TV shows on the Top 250 Rated Charts?
The following formula is used to calculate the Top Rated 250 titles. This formula provides a true 'Bayesian estimate', which takes into account the number of votes each title has received, minimum votes required to be on the list, and the mean vote for all titles:
weighted rating (WR) = (v ÷ (v+m)) × R + (m ÷ (v+m)) × C
Where:
R = average for the movie (mean) = (Rating)
v = number of votes for the movie = (votes)
m = minimum votes required to be listed in the Top 250 (currently 25,000)
C = the mean vote across the whole report
Please be aware that the Top Rated Movies Chart only includes theatrical features: shorts, TV movies, miniseries and documentaries are not included in the Top Rated Movies Chart. The Top Rated TV Shows Chart includes TV Series, but not TV episodes or Movies. - Public Badges and Private Ratings, An Explanation.
Our ratings privacy flag can be set to make your actual film or show rating only visible to you. However we may at our discretion unilaterally grant you a publicly-viewable badge or other forms of publicly viewable recognition based on the fact that you rated or checked-in for a title (while still withholding showing your rating). For the subset of badges based on completing a rating-based list, if you unrate any or all titles that contributes to gaining the badge, the badge will disappear shortly.
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