3, we draw a conclusion that the accuracy of SBFL would not be affected by the class ratio of failed to passed test cases when we change the class ratio using a nonrandom PNF strategy.
4) At least keeping the same fault localization accuracy of SBFL as the original test suite.
The three figures show that class ratio has effect on fault localization performance when using random strategy to generate test suite for all four SBFL techniques.
Figure 3(b) about Space program indicates that the four classical SBFL techniques could get better fault localization accuracy with a more balanced test suite using random strategy.
In experiment, we also found that the score of different faulty versions has a significant difference with the same SBFL method, while the results of some version have same tendency.
Every suspiciousness calculation of SBFL method is closely related to the number of passed and failed test cases.
The experiments indicated the PNF strategy is effective for SBFL.