About the Kinsey Scale
Alfred Kinsey was the one of the greatest sex and gender researchers of the twentieth century. During his 1940's study of homosexuality, he devised his 7-step scale to describe degrees of homosexuality and heterosexuality.
0 - exclusively heterosexual
1 - predominantly heterosexual, incidentally homosexual
2 - predominantly heterosexual, but more than incidentally homosexual
3 - equally heterosexual and homosexual
4 - predominantly homosexual, but more than incidentally heterosexual
5 - predominantly homosexual, incidentally heterosexual
6 - exclusively homosexual
He used as measurement the factors of mental inclination (fantasies, dreams, and thoughts) and practice (frequency of sexual activities and emotional feelings).
While Kinsey's findings seemed very applicable at the time, today it is viewed as flawed. There are simply not enough parameters, and there was no category for gender, which in itself is a multidimensional concept. When gender is added to the scale, fluctuations are better explained and any differences between the sexual orientations of transgendered persons and non-transgendered persons becomes more apparent.