The cannibal boom is a period in the history of exploitation film, lasting roughly from 1977 to 1981, where cannibal films were at the peak of their popularity in Grindhouse theaters and cinema.
 Though Umberto Lenzi started the cannibal genre with his film "Man from Deep River" in 1972, it was not until Ruggero Deodato released his film "Last Cannibal World" in 1977 that the concept of cannibal films began to catch on.
 Although five cannibal films were made in 1977 and 1978, none were released in 1979 (though Deodato's "Cannibal Holocaust" was in the works).
 In February 1980, Deodato released "Cannibal Holocaust", which was the start of a chain of seven similar films to be made and released in the same year.
 The following year, however, in 1981, only two cannibal films were made (one of them was "Cannibal Ferox", second in notoriety only to "Cannibal Holocaust").
 Only four other cannibal films were made after 1981 until the fad's conclusion in 1988 with Antonio Climati's "Natura Contro".
A film genre is a motion picture category based on similarities in either the narrative elements or the emotional response to the film (namely, serious, comic, etc.).
 Most theories of film genre are borrowed from literary genre criticism.
 The basic genres include fiction and documentary, from which subgenres have emerged, such as docufiction and docudrama.
 Other subgenres include the courtroom and trial-focused drama known as the legal drama.
 Types of fiction which may seem unrelated can also be combined to form hybrid subgenres, such as the melding of horror and comedy in the "Evil Dead" films.
 Other popular combinations are the romantic comedy and the action comedy film.
The actuality film is a non-fiction film genre that, like the documentary film, uses footage of real events, places, and things, yet unlike the documentary is not structured into a larger argument, picture of the phenomenon or coherent whole.
 In practice, actuality films preceded the emergence of the documentary.
 During the era of early cinema, actualities—usually lasting no more than a minute or two and usually assembled together into a program by an exhibitor—were just as popular and prominent as their fictional counterparts.
 The line between "fact" and "fiction" was not so sharply drawn in early cinema as it would become after the documentary came to serve as the predominant non-fiction filmmaking form.
 An actuality film is not like a newspaper article so much as it is like the still photograph that is published along with the article, with the major difference being that it moves.
 Apart from the traveling actuality genre, actuality is one film genre that remains strongly related to still photography.
The Iatmul are a large ethnic group of about 10,000 people inhabiting some two-dozen politically autonomous villages along the middle Sepik River in Papua New Guinea.
 The communities are roughly grouped according to dialect of the Iatmül language as well as sociocultural affinities.
 The Iatmul are best known for their art, men's houses, male initiation, elaborate totemic systems, and a famous ritual called "naven", first studied by Gregory Bateson in the 1930s.
 More recently, the Iatmul are known as a location for tourists and adventure travelers, and a prominent role in the 1988 documentary film "Cannibal Tours".
Keith Konrad Slettedahl (born August 9, 1973) is an American musician.
 He is the singer and songwriter for Los Angeles pop rock group The 88.
 In 2006, he appeared in the episode "Best Prom Ever" on the sitcom "How I Met Your Mother", playing a gig with his band on a High School-Prom.
Cannibal Tours is a 1988 quasi-documentary film by Australian director and cinematographer Dennis O'Rourke.
 While it borrows heavily from ethnographic modes of representation, the film is a biting commentary on the nature of modernity.
 The film is also widely celebrated for its depiction of Western touristic desires and exploitation among a 'tribal' people.
The World's Best Prom is a 2006 documentary film about a high school prom in Racine, Wisconsin.
 "Prom" was released as a short film and was expanded to feature-length documentary length.
 It was released in its longer form on April 4, 2006.
 It was filmed on location in Racine and was shot entirely in digital video.
 This film was originally a 17-minute short film of the same name which won Best Documentary at the Wisconsin Film Festival.
 The film was also re-edited as mini-episodes for Truth, but the episodes never aired.
Student Bodies is a 1981 comedy horror film written and directed by Mickey Rose, with an uncredited Michael Ritchie co-directing.
 A spoof of slasher horror films such as "Halloween", "Friday the 13th," and "Prom Night".
 "Student Bodies" was the first film to satirize the thriving slasher film genre.
 A prominent feature of the film is a body count that is superimposed onscreen whenever a death occurs.
The woman's film is a film genre which includes women-centered narratives, female protagonists and is designed to appeal to a female audience.
 Woman's films usually portray "women's concerns" such as problems revolving around domestic life, the family, motherhood, self-sacrifice, and romance.
 These films were produced from the silent era through the 1950s and early 1960s, but were most popular in the 1930s and 1940s, reaching their zenith during World War II.
 Although Hollywood continued to make films characterized by some of the elements of the traditional woman's film in the second half of the 20th century, the term itself disappeared in the 1960s.
 The work of directors George Cukor, Douglas Sirk, Max Ophüls, and Josef von Sternberg has been associated with the woman's film genre.
 Joan Crawford, Bette Davis, and Barbara Stanwyck were some of the genre's most prolific stars.
"Best Prom Ever" is the 20th episode in the first season of the television series "How I Met Your Mother".
 It originally aired in the United States on May 1, 2006.
 It had the lowest recorded viewership for season 1 (7.24 million).

Question: What film genre do The World's Best Prom and Cannibal Tours fall into?
Answer: documentary