The document discusses how the authors researched various horror subgenres to understand conventions and select one for their trailer. They chose the slasher subgenre, which includes iconic films like Halloween, A Nightmare on Elm Street, and Scream. The authors felt they could create a realistic and conventional slasher trailer that would appeal to the target audience. Their research also revealed Wes Craven as an influential director in the slasher genre who inspired them.