Seeing as they define “user failure” as
it seems pretty clear that they did not make this important distinction.
Here is where I am getting my info, in case you are curious.
From
Taking Charge of Your Fertility, a very well received book now available in its 10th anniversary addition, written by a nationally respected, secular, ABC approving, Women’s Health educator and speaker, Toni Weschler:
Emphasis is authors.
It seems pretty clear that the accepted average user failure rate is
much lower than that claimed by this one survey, and that even with the lower accepted user failure rate much of it is on account of people’s
intentional decisions to not follow the method. Since this book is from someone who has nothing against contraception as such, even suggesting using the barrier method during fertile periods, its pretty clear she’s not just twisting or ignoring data from some anti-ABC bias. Also, if this claim she is making about the effectiveness of this method were false, I think someone would have pointed it out to her and forced her to fix it after 10 years of publication.