Ancillary features

Ancillary features

 
User ratings of films
IMDb top 250 films, plotted by year and the sum of the ratings for movies from that year.

As one adjunct to data, the IMDb offers a rating scale which allows users to rate films by choosing one of ten categories in the range 1–10, with each user able to submit one rating. The points of reference given to users of these categories are the descriptions "1 (awful)" and "10 (excellent)"; and these are the only descriptions of categories. Due to the minimum category being scored one, the mid-point of the range of scores is 5.5, rather than 5.0 as might intuitively be expected given a maximum score of ten. This rating system has also recently been implemented for television programming on an episode-by-episode basis.

In adopting this method, IMDb is following its widespread usage; the method is the same as rating in the range of a half star to five stars. When used in reviews by a single reviewer, the method has some basic utility given a rating is usually given in the context of a qualitative appraisal of the film. The simplicity of this method makes it popular, but in terms of psychometric, statistical, and other criteria, the method suffers shortcomings (see online rating scales).


Filters and weights

IMDb indicates that submitted ratings are filtered and weighted in various ways in order to produce a weighted mean that is displayed for each film, series, and so on. It states that filters are used to avoid vote stuffing; the method is not described in detail to avoid attempts to circumvent it.

 
Ranking

The IMDb Top 250 is intended to be a listing of the top 'rated' 250 films, based on ratings by the registered users of the website using the methods described.[7] Only non-documentary theatrical releases running at least forty-five minutes with over 1300 ratings are considered; all other products are ineligible[8]. Also, the 'top 250' rating is based on only the ratings of "regular voters" (IMDb does not define this term). In addition to other weightings, the top 250 films are also based on a weighted rating formula referred to in actuarial science as a credibility formula.[9] This label arises because a statistic is taken to be more credible the greater the number of individual pieces of information; in this case from eligible users who submit ratings. IMDb uses the following formula to calculate the weighted rating:


where:
= Weighted Rating
= average for the movie as a number from 0 to 10 (mean) = (Rating)
= number of votes for the movie = (votes)
= minimum votes required to be listed in the Top 250 (currently 1300)
= the mean vote across the whole report (currently 6.7)

An extended listing of the Top 500 - following the same formula - is available to IMDbPro subscribers.

The IMDb also has a Bottom 100 feature which is assembled in the same way.[10] Although the Top 250 films generally do not shift much (the "great" films are typically better known, and therefore have a high number of votes and a higher popularity inertia) the "winner" of the Bottom one hundred changes frequently. The potential for skewing bottom 100 film ratings resulted in an apocryphal account during IMDb's early years in which a disproportionate number of "Bottom 100" films were featured on Mystery Science Theater 3000, which is said to be a result of an MST3K website encouraging all its users to register with IMDb and vote "1" on films featured on the show.

The top 250 list comprises a wide strata of films, including major releases, cult films, independent films, critically acclaimed films, silent films and foreign films.

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Plot-related features and spoiler warnings

IMDb main pages for each film include one or more of the sections titled Plot outline, Plot synopsis, and Plot keywords, and separate pages for Plot summary and Plot synopsis. The Plot synopsis pages are accessed through links that notify the reader a spoiler may be included.[11]

The plot outline is a short summary of the premise with a general overiew, usually not including details that may be considered to be spoilers. The plot outline is presented on the main page for the film if short enough, and if it extends beyond a couple of lines includes a "more" link that opens to the Plot summary page for the film.

On the Plot summary page, IMDb includes the full text of the plot outline, along with the first few lines of the plot synopsis, followed by a link to a further more detailed page, with the link text written as "more (warning! contains spoilers)".[12]

The plot synopsis is a more complete summary of the plot that can be edited by readers of IMDb, often including twists and turns that some readers may consider to be spoilers and may not want to know about if they have not yet seen the film.[13] IMDB places the synopsis on a separate page, with a link on the film's main page using text that advises the reader as follows: "View full synopsis. (warning! may contain spoilers)". The separate Plot synopsis page includes the headline "Warning! This synopsis contains spoilers. See plot summary for non-spoiler summarized description."[14]

The IMDb User's Guide advises user contributors to avoid revealing spoilers outside of the synopsis section where they are covered by the spoiler warning in the page headline. IMDb also provides a spoiler warning template for use when spoilers occur in an unexpected location, for example, according to their help page, when a synopsis includes a spoiler for a different movie.[13] In the IMDb Submission Guide for the "Trivia and Goofs" page section and for their message boards, the guide states that spoilers should be avoided in general in those sections, but that if a spoiler is included, it must be preceded by an announcement, such as using the word "SPOILER:" or their provided spoiler template. [15][16][17]

Plot keywords are keywords that contributors to the IMDb submit. These are keywords regarding objects and occurrences in each film on the IMDb.[18]

  
Message boards

One of the most used features of the Internet Movie Database is the Message Boards that coincide with every title (excepting TV episodes) and name entry, along with forty-seven Main Boards. These boards allow registered users to share, discuss and debate information about the movie and/or people that worked on it. They were not originally part of the IMDb, but were added only after its purchase by Amazon.com, some time in the year 2000.

As the IMDb expires older posts from all message boards variably, it is difficult to precisely measure traffic according to individual board, but the Soapbox and the Sandbox are amongst the highest traffic boards on IMDb. The Soapbox is a general purpose discussion board, where users can go for "their more heated discussions".[19] The Sandbox is a general purpose, anything-goes board designated for test messages and off-topic posts.

Boards for various political persons (most notably President George W. Bush) have also been used for political discussion. On May 9, 2007, a "Politics" message board was created.

 
My movies

Registered users also have access to "my movies," which is a database that can be created by any registered user.[22] The user can sort the content of that database according to several criteria, such as vote history.