ScoringFunction scoringFunction = null;
if(scoringFunctionClass.equals(BM25ScoringFunction.class.getName())) {
float k1 = Float.parseFloat(element.getAttribute("k1"));
float b = Float.parseFloat(element.getAttribute("b"));
scoringFunction = new BM25ScoringFunction(k1, b);
} else if(scoringFunctionClass.equals(DirichletScoringFunction.class.getName())) {
float mu = Float.parseFloat(element.getAttribute("mu"));
scoringFunction = new DirichletScoringFunction(mu);
} else if(scoringFunctionClass.equals(TfScoringFunction.class.getName())) {
scoringFunction = new TfScoringFunction();