All are methods accepted by the Catholic Church as valid natural family planning methods. All have method effectiveness rates of up to 99% for avoiding a pregnancy. All methods observe the primary sign of fertility, cervical mucus. All methods require charting and abstaining from conjugal love during the fertile time in the woman's cycle to avoid pregnancy.
Although the Ovulation Method teaches several external signs of fertility, it focuses on one major sign of fertility, cervical mucus as experienced at the vulva. Creighton Model FertilityCare teaches observation of the cervical mucus using a standardized descriptive model and works to identify biomarkers that can help diagnose and treat various reproductive disorders & infertility. The Sympto-Thermal Method correlates information from three signs of fertility: temperature, mucus and cervical changes as experienced at the cervix.
Differences between the the methods lie in the interpretation of the signs of fertility, and in the way ovulation is determined.