Although film genres have changed and spread considerably since the 1930s, they remain a critical measure of audience expectations as well as of a film’s ability to satisfy or disappoint, and surprise or bore, the movie viewer.

Film genres classify viewers’ experience and understanding of a movie. A generic perspective on a movie can be either prescriptive or descriptive. Both prescriptive and descriptive approaches can point viewers to particular ways of understanding a film.

Prescriptive approaches assume that 1) a model for a genre preexists any particular films in that genre; 2) a successful genre film deviates as little as possible from that model; and 3) a viewer can and should be objective in determining a genre.

Descriptive approaches assume that 1) a genre develops and changes over time; 2) a successful genre film builds on older films and develops in new ways; 3) a viewer can and should acknowledge that his or her subjectivity helps determine a genre.

The significance of a particular film’s engagement with genre conventions and histories is also shaped by its situation within classical or revisionist traditions. Related to prescriptive values, classical generic traditions establish relatively fixed sets of formulas and conventions associated with certain films or with specific places in history. Stemming from descriptive approaches, revisionist genre traditions see films as functions of changing historical and cultural contexts that modify the conventions and formulas of specific genres.

Additionally, classical genres can be viewed as both historical and structural paradigms. A historical paradigm presumes that a genre evolved to a point of perfection at some point in history and that one or more films at that point describe the generic ideal. A structural paradigm relies less on historical precedent than on a formal or structural ideal that may or may not be actually seen, in a complete or pure form, in any specific film.

In contrast, generic revisionism assumes genres continually change; films within a genre adapt their conventions and formulas to reflect different times and places. Some modern films exhibit generic reflexivity, that is, they are self-conscious about their generic identity and visibly comment on generic paradigms.

Although major Hollywood genres may be the most recognizable, we also notice generic patterns in films connected to more specific times, places, events, and cultures—what we might call “local” genres. These include such culturally specific genres such as Japanese jidai-geki films and the Austrian and German heimat films.