Theorist one: Propp.
Propps theory is a form of structuralism. He identified 8 charcter roles.
The 8 character roles include:
The villain
The hero
The donor
The helper
The princess
Her father
The dispatcher
The false hero
These structures are often culturally derived and form expectations in the mind of an audience from within that same culture e.g. fairy tales always have happy endings or the princess always marries the handsome prince.
Propps theory can be applied to generic structures in western culture such as popular film genres, therefore genre structures form expectations in the mind of an audience that certain rules apply to the narrative. However, cultural change can force structures to change e.g. a hero can now be a woman.
Theorist two: Gustav Freytag
In 1863, the German novelists Gustav Freytag published Die Technik Des Dramas in which he outlines his pyramid structure for the plot. Adapting Aristotle's basic triangle he added the idea of the plot complicating, introducing conflicts and building to a climax point, after which it falls away when the conflicts are resolved, the mysteries are also solved and we are finally left with a satisfactory resolution.

Rising action: The series of complications, conflicts and and layers of mystery that build toward the climax.
Climax: The turning point and the point with the highest intensity, emotionally or through action.
Falling action: Action following the climax and pieces of the jigsaw falling in to place to solve the mysteries.
Resolution: Any disruptions caused by the rising action are returned to a state or 'normality', the mysteries are solved and as far as possible the established order of the start is returned. However where it can not return to the established order, justice is served.
Freytag's structure is noticeable in Hollywood output and is striking feature of Hollywood film trailers. The form of the triangle used below best represents the timing and the structure used in many film trailers where a quiet opening builds to a punch in the music, followed by rapid action and a falling away to a quiet sound and the credits at the end.

Many different types of media that tell a story e.g Music video, films, film trailers and novels follow Freytag's theory as it is a very effective way of creating drama. If they do not follow this theory it is very unconventional.
Theorist three: Tzvetan Todorov
Freytag's theory was further developed in 1960s by Tzvetan Todorov in to his theory of equilibrium - disequilibrium - equilibrium. Todorov was a bulgarian structuralist, he developed the theory of disrupted equilibrium.He reailsed that stories follow a typical pattern of:
equilibrium - The status quo when things are as they should be.
disequilibrium - The status quo is disrupted by an event.
equilibrium - The status quo is restored at the end of the story by the actions of the hero.
Todorov later developed this into a 5 stage pattern
1) A state of equilibrium at the outset
2) A disruption of the equilibrium by some action
3) A recognition that there has been a disruption
4) An attempt to repair the disruption
5) A reinstatement of the equilibrium
Theorist four: Roland Barthes
According to Barthes, there are 5 action codes that enable an audience to make sense of a narrative.
*Hermeneutic - (narrative turning point) we know where the story will go next.
*Proairetic - (basic narrative actions) e.g. detective interviews suspect ( similar
to propps 31 functions)
*Cultural - (prior social knowledge) e.g. our attitudes to gender or racial
stereotypes.
*Semic - (medium related codes) intertextuality.
*Symbolic - (themes) iconography or a theme such as image versus reality
All the theories I have mentioned above I will try to use in my horror film e.g propps theory by clearing demonstrating who the villain is and who are the victims. I will also use Freytag's and Todorov's theory as the trailer will begin with them peacfully setting off, climax in the middle when the victims are being murdered and finally when 'the survivour' is running away its an attempt to repair te disruption. That is when Barthes theory comes in as the audience members will have some knowledge of horrors before hand therefore they know the victim will either survive or it will be left a cliffhanger.