It’s the question that never dies. Men and women have been debating it for years—is it the size of the wave or the motion of the ocean? Scientists think they have an answer.

According to a new study, penis size does matter … kind of. And only for some women and for certain types of orgasms. The study, published in the Journal of Sexual Medicine, found that women who have frequent vaginal orgasms are more likely to do so with men who have larger penises. The same goes for women who say they prefer penile-vaginal intercourse over other types of sex.

The study asked 323 women to recall their past sexual encounters and answer questions about how important penile-vaginal intercourse and other sex acts were to them, along with whether or not penis length affected their ability to orgasm through vaginal stimulation. They also asked the women if they were more likely to orgasm vaginally with a longer- or shorter-than-average penis. (For those of you frantically looking for measuring tape, they defined average as between 5.8 and 6.1 inches long—about the size of a U.S. dollar bill, for handy measuring purposes.)

About half (160) of the women in the study had vaginal orgasms and enough experience to compare size experiences with past partners. That’s significantly different than the oft-quoted stat that 75 percent of women don’t orgasm through intercourse alone. Of these 160 women, 60 percent actually said size made no difference, but a statistically significant number (33.8 percent) said they preferred longer-than-average size. 6.3 percent preferred partners with shorter-than-average penises.

For some researchers, this study goes into a murky area, making women feel like there is a “right” or “better” way to orgasm. “Women who orgasm through vaginal stimulation may indeed prefer longer penises, but not everyone prefers to orgasm that way,” female sexual response researcher Barry Komisaruk told LiveScience. Beverly Whipple, one of the discoverers of the G-spot, chimes in, warning against getting worked up over these findings. “To me, all of this is just so goal-oriented, and it’s difficult for me to see researchers setting up another goal [vaginal orgasm] for women to experience,” she said.