A procedural or procedural drama is a cross-genre type of literature, film, or television program involving a sequence of technical detail. A documentary film may also be written in a procedural style to heighten narrative interest. Procedurals are often criticized for being formulaic. Procedurals are also generally less character-driven than serialized shows. However, some procedurals have more character emphasis than is typical of the format. Some may occasionally feature a storyline stretching over several episodes (often called a story arc). A popular subgenre is the police procedural.