protected double computeConfidence() { return 1 - Math.pow(.9, elts); }
protected double computeConfidence() { return 1 - Math.pow(.5, ppt.num_samples()); }
public int derivedDepth() { return 1 + Math.max(base1.derivedDepth(), Math.max(base2.derivedDepth(), base3.derivedDepth())); }