A method for projecting leakage performance for an absorbent article includes applying a liquid insult to a first sample article on a testing apparatus and recording leakage, applying a liquid Insult to a second sample article on the testing apparatus and recording leakage, and calculating a projected frequency of actual leakage for the absorbent article according to a linear regression formula. A method of designing an absorbent article includes determining a maximum acceptable frequency of overnight leakage for the article, calculating a target Static Retention Index, testing the absorbent article to determine an average mannequin leakage value, and modifying the absorbent article structure to adjust the average test mannequin leakage value until the average test mannequin leakage value is substantially equal to the target Static Retention Index. A training pant includes a core having a Static Retention Index of less than about 1.4 g.