Primary research involves directly questioning a target audience to inform planning, while secondary research uses existing audience data. An analysis of three horror/thriller films found that the 15-24 age group was the most common viewers, making up over half the audience for The Haunting in Connecticut. For Insidious and The Exorcism of Emily Rose, this age group was also the primary viewers due to teenagers' interest in the genres. The gender ratios varied by film but were generally evenly split between male and female viewers.