Internet Movie Database

The Internet Movie Database (IMDb) is an online database of information related to movies, television shows, actors, production crew personnel, video games and fictional characters featured in visual entertainment media. It is one of the most popular online entertainment destinations, with over 100 million unique users each month and a solid and rapidly growing mobile presence. IMDb was launched on October 17, 1990, and in 1998 was acquired by Amazon.com.

History before website
IMDb originated from a single list started as a hobby by English film enthusiast Col Needham (Founder and CEO of IMDb) in early 1987. The founding ideas of IMDb began with a posting by Col Needham titled "Those Eyes", on the subject of actresses with beautiful eyes. On October 17, 1990, Col Needham posted a simple software package to the USENET newsgroup rec.arts.movies, which allowed readers of that group to create and search a basic movie and TV database. The original database was built from the lists of credits that Col Needham and two other readers had begun to publish on the rec.arts.movies group. Other film fans began to participate in the collection of data on the Usenet newsgroup rec.arts.movies.

Needham soon started a (male) "Actors List", while Dave Knight began a "Directors List", and Andy Krieg took over THE LIST, which would later be renamed the "Actress List". Both this and the Actors List had been restricted to people who were still alive and working, but retired people began to be added, and Needham also started what was then (but did not remain) a separate "Dead Actors/Actresses List". The goal now was to make the lists as inclusive as the maintainers could manage. In late 1990, the lists included almost 10,000 movies and television series. On October 17, 1990, Needham posted a collection of Unix shell scripts which could be used to search the four lists, and the database that would become the IMDb was born. At the time, it was known as the "rec.arts.movies movie database".

On the web
By 1992, the database had been expanded to include additional categories of filmmakers and other demographic material, as well as trivia, biographies, and plot summaries; the movie ratings had been properly integrated with the list data; and a centralized email interface for querying the database had been created by Alan Jay. Later in the year, it moved onto the World Wide Web (a network in its infancy at that time) under the name of Cardiff Internet Movie Database. The database resided on the servers of the computer science department of Cardiff University in the UK. Rob Hartill was the original web interface author. In 1994, the email interface was revised to accept the submission of all information, meaning that people no longer had to email the specific list maintainer with their updates. However, the structure remained that information received on a single film was divided among multiple section managers, the sections being defined and determined by categories of film personnel and the individual filmographies contained therein. Its management also continued to be in the hands of a small contingent of underpaid or volunteer "section managers" who were receiving ever-growing quantities of information on films from around the world and across time from contributors of widely varying levels of expertise and informational resources. Despite the annual claims of Needham, in a year-end report newsletter to the Top 50 contributors, that "fewer holes" must now remain for the coming year, the amount of information still missing from the database was vastly underestimated. Over the next few years, the database was run on a network of mirrors across the world with donated bandwidth.

The website is Perl-based. As of May 2011, the site has been filtered in China for more than one year, although many users address it through proxy server or by VPN.

On October 17, 2010, IMDb launched original video (www.imdb.com/20) in celebration of its 20th anniversary.

As an independent company
In 1996, IMDb was incorporated in the United Kingdom, becoming the Internet Movie Database Ltd. Founder Col Needham became the primary owner as well as the identified figurehead. General revenue for site operations was generated through advertising, licensing and partnerships.

As Amazon.com subsidiary
In 1998, Jeff Bezos, founder, owner and CEO of Amazon.com, struck a deal with Col Needham and other principal shareholders to buy IMDb outright and attach it to Amazon as a subsidiary, private company. This gave IMDb the ability to pay the shareholders salaries for their work, while Amazon.com would be able to use the IMDb as an advertising resource for selling DVDs and videotapes.

IMDb continued to expand its functionality. On January 15, 2002 it added a subscription service known as IMDbPro, aimed at entertainment professionals. IMDbPro was announced and launched at the 2002 Sundance Film Festival. It provides a variety of services including film production and box office details, as well as a company directory.

As an additional incentive for users, as of 2003, if users are identified as being one of "the top 100 contributors" in terms of amounts of hard data submitted, they receive complimentary free access to IMDbPro for the following calendar year; for 2006 this was increased to the top 150 contributors, and for 2010 to the top 250. In 2008 IMDb launched their first official foreign language version with the German IMDb.de. Additionally in 2008 IMDb acquired two other companies. Withoutabox and Box Office Mojo.

In 2011 IMDb was sued by an unknown actress for more than US$1 million due to IMDb revealing her age. The actress claims that revealing her age could cause her to lose acting opportunities.

TV episodes
On January 26, 2006, "Full Episode Support" came online, allowing the database to support separate cast and crew listings for each episode of every TV series. This was described by Col Needham as "the largest change we've ever made to our data model", and increased the number of titles in the database from 485,000 to nearly 755,000.

Shortly after, the database entries for TV series are in a state of flux, as listings are migrated from series titles to individual episodes. The maintainers anticipated "a couple of months for data to settle down and bugs to be ironed out", but inaccuracies were still present one year later.

Characters filmography
On October 2, 2007, the characters filmography feature was launched. The feature is similar to the existing title, name and company feature, except now users can see by whom a certain character was played and can read a biography about the character and memorable quotes from him or her. All data in the characters filmography is submitted by regular users and is largely not verified by the IMDb staff, in contrast to most other data submitted to the site, which is first verified and might be rejected by the staff. This lack of oversight is acceptable, however, because very little new data is sent in; the majority of submissions consist of existing data being connected together.

Instant viewing
On September 15, 2008, a feature was added that enables instant viewing of over 6,000 movies and television shows from CBS, Sony and a number of independent film makers, with direct links from their profiles.

Due to licensing restrictions, this feature is only available to viewers in the United States.

User ratings of films
As one adjunct to data, the IMDb offers a rating scale that 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 since 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. The simplicity of this method makes it popular, but in terms of psychometric, statistical and other criteria, the method suffers shortcomings.

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 ballot stuffing; the method is not described in detail to avoid attempts to circumvent it. In fact, it sometimes produces an extreme difference between the weighted average and the arithmetic mean. For example, Jonas Brothers: The 3D Concert Experience is considered to be the worst film with a weighted average of 1.3 as of March 2009, but has a rather ordinary arithmetic mean of 4.1.

Ranking (IMDb Top 250)
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. Only non-documentary theatrical releases running at least forty-five minutes with over 3000 ratings are considered; all other products are ineligible. Also, the 'top 250' rating is based on only the ratings of "regular voters". The exact number of votes a registered user would have to make to be considered to be a user who votes regularly has been kept secret. IMDb has stated that to maintain the effectiveness of the top 250 list they "deliberately do not disclose the criteria used for a person to be counted as a regular voter". 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. 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:


 * $$W = \frac{Rv + Cm}{v+m} $$

where:


 * $$W\ $$ = Weighted Rating


 * $$R\ $$ = average for the movie as a number from 0 to 10 (mean) = (Rating)


 * $$v\ $$ = number of votes for the movie = (votes)


 * $$m\ $$ = minimum votes required to be listed in the Top 250 (currently 3000)


 * $$C\ $$ = the mean vote across the whole report (currently 6.9)

The $$W\ $$ in this formula is equivalent to a Bayesian posterior mean (See Bayesian statistics).

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 through a similar process although only 1500 votes must be received to qualify for the list.

The top 250 list comprises a wide range of films, including major releases, cult films, independent films, critically acclaimed films, silent films and non-English language films.

Criticisms of IMDb ranking
The validity of the Top 250 has come under scrutiny. The skepticism includes accusations of ballot-box stuffing or voting ambiguity. IMDb allows users to rate films long before their completion (so before the reviewer has actually seen the film).

Soon after its release, WALL-E garnered high ratings from users, eventually pushing it to #6 on the list. Soon afterwards, WALL-E's message board became filled with posts from users urging others to vote it a "1", after which its rating dropped significantly.

Other skepticism has revolved around The Godfather. While many of the top films on IMDb have less than 4% of their total votes at "1", The Godfather has maintained a significantly higher percentage, coming in at 6.2% averaged over the last 5 years.

Some films see a spike in "10" votes around the time the movie is first released, and then as time passes, these films' ratings decrease. For instance, Up found its way to the #18 spot on IMDb's list shortly after it was released, but as of the 18th of November, 2011, it has fallen to the #104 spot.

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.

The plot outline is a short summary of the premise with a general overview, 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)".

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. 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."

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. 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.

Plot keywords are keywords that contributors to the IMDb submit. These are keywords regarding objects and occurrences in each film on the IMDb. By adjusting one's preferences, users can have these keywords hidden if they have not rated the film. Otherwise, the keywords are revealed by hovering the mouse over the hidden text.

In the most recently updated version of the IMDb website, plot keywords are no longer covered by spoiler tags or obscured.

Message boards
One of the most used features of the Internet Movie Database is the message boards that coincide with every title (excepting, as of 2010, TV episodes) and name entry, along with over 140 main boards. This section is one of the more recent features of IMDb, having its beginnings in 2001. In order to post on the message boards a user needs to "authenticate" their account via cell phone, credit card, or by having been a recent customer of the parent company Amazon.com.

Data provided by subjects
In 2006, IMDb introduced its "Résumé subscription service", where actors and crew can post their own résumé and upload photos of themselves for a yearly fee. The base annual charge for including a photo with an account was $39.95 until 2010, when it was increased to $54.95. IMDb résumé pages are kept on a sub-page of the regular entry about that person, with a regular entry automatically created for each résumé subscriber who does not already have one.

Copyright, vandalism, and error issues
All volunteers who contribute content to the database technically retain copyright on their contributions but the compilation of the content becomes the exclusive property of IMDb with the full right to copy, modify, and sublicense it and they are verified before posting. Credit is not given on specific title or filmography pages to the contributor(s) who have provided information. Conversely, a credited text entry, such as a plot summary, may be "corrected" for content, grammar, sentence structure, perceived omission or error, by other contributors without having to add their names as co-authors.

Due to the process of having the submitted data or text reviewed by a section manager, IMDb is different from database projects like Wikipedia, Discogs, or OpenStreetMap in that contributors cannot add, delete, or modify the data or text on whim, and the manipulation of data is controlled by IMDb technology and salaried staff. The advantage is, there is less incentive for vandals to attack the system, although incidents have been reported.

The Java Movie Database (JMDB) is reportedly creating an IMDb_Error.log file that lists all the errors found while processing the IMDb plain text files. A Wiki alternative to IMDb is omdb (Open Media Database) whose content is also contributed by users but licensed under CC-by and the GFDL. Since 2007, IMDb has been experimenting with wiki-programmed sections for complete film synopses, parental guides, and FAQs about titles as determined by (and answered by) individual contributors.

Data format and access
IMDb does not provide an API for automated queries. However most of the data can be downloaded as compressed plain text files and the information can be extracted using the command-line interface tools provided.

Beside that there is the Java based GUI application available that is able to process the compressed plain text files and allow to search and display the information. This GUI application supports different languages but the movie related data is of course English as made available by IMDb. A Python package called IMDbPY can also be used to process the compressed plain text files into a number of different SQL databases, enabling easier access to the entire dataset for searching or data mining.

Film titles
The IMDb has sites in English as well as versions translated completely or in part into other languages (Portuguese, Finnish, French, German, Hungarian, Italian, Polish, Romanian and Spanish). The non-English language sites display film titles in the specified language. While originally the IMDb's English-language sites displayed titles according to their original country-of-origin language, in 2010 the IMDb began displaying titles by either their US or UK AKA, depending on the user's location. For those who wish to use the English-language sites and still see titles listed by their original title users can update their site settings with that preference or use the IMDb's AKA website.