Linked article passed along by someone in the comments section (thanks!).
Before Kinsey, sexual orientation was classified predominantly as heterosexual or homosexual. In the 1940s, Kinsey introduced a new way of thinking about sexual orientation. He viewed it as a continuum with the anchor points being 100% heterosexual and 100% homosexual. In between were shades of grey, or bisexuality. When he created a corresponding scale to measure sexual orientation, he focused on sexual behaviour as the indicator. Here's what it looked like:
This model persisted until the 1980s when Storm introduced a model that conceptualized sexual orientation not as a single continuum, but as two unrelated but interacting continuums: interest in people of the same sex (homoeroticism), and interest in people of the opposite sex (heteroeroticism). People were scored on both continuums:
This model proved to be much more helpful and importantly, it includes the experiences of people who identify as asexual.
The article linked below describes another model. The model was proposed by a non-academic man who identifies as heteroromantic asexual. He felt that other models of sexual orientation didn't apply to his identity and experiences. While the model isn't entirely effective, it's still an interesting approach to thinking about sexual orientation and identity.
Snippets from the article published at Connections.Mic:
Parks decided to develop a more comprehensive alternative: the Purple-Red Scale of Attraction, which he recently posted on /r/Asexuality. Like the Kinsey scale, the Purple-Red scale allows you to assign a number from zero to six to your level of same-sex or heterosexual attraction, but it also lets you label how you experience that attraction on a scale of A to F. A represents asexuality, or a total lack of interest in sex "besides friendship and/or aesthetic attraction," while F represents hypersexuality.
Parks told Mic that he came up with the idea for the Purple-Red scale after learning about asexuality and realizing that he was a "heteroromantic asexual, or a B0 on the scale" — someone who is interested exclusively in romantic, nonsexual relationships with the opposite sex.
"I then thought, not only are there sexual and asexual people, [but] there are different kinds of sexual people as well," he said. "I thought of adding a second dimension to Kinsey's scale to represent different levels of attraction." (As for the color scheme, Parks opted for purple because of its designation as the official color of asexuality, while "'red-blooded' is a term often used to describe someone who is hypersexual.)
Read the rest here.