To determine whether it is more likely that two individuals are full vs. half siblings, you can compare the Combined Sibship Index ("sibship index") values obtained for the full and half sibling relationships.
If the Full Sibship Index is greater than the Half Sibship Index, then the individuals are more likely to be full siblings. Likewise, if the Half Sibship Index is greater than the Full Sibship Index, then the individuals are more likely to be half siblings.
To calculate the likelihood of the full vs. half sibling relationship, the sibship index values can be directly compared. For example, if a sibling pair has a Full Sibship Index of 100 and a Half Sibship Index of 2, then they are 50 times more likely to be full siblings than half siblings.
Similarly, if a sibling pair has a Full Sibship Index of 1.5 and a Half Sibship Index of 20, then they are 13.33 times more likely to be half siblings than full siblings (20 ÷ 1.5 = 13.33).