The term combined paternity index, sometimes simply referred to as CPI, is very pertinent to the DNA test results of a paternity test. The strength of genetic evidence in a paternity test is referred to as the paternity index. The number generated from the paternity index will show how many times more likely an individual is the father to a child than another person in the population of your race. A DNA test involves close analysis of 15 loci and for each of these loci a paternity index is calculated. Multiplication of the individual paternity indexes at each locus will results in the combined paternity index which will determine whether the alleged father is the true biological father by 99.99% and exclude the alleged father by 100%. You can find more information about this on Understanding Your Paternity Test Result.