### Question:
RaschFitStatistics { public double varianceOfResponse(ItemResponseModel irm, double theta){ double Wni = 0.0; double Eni = irm.expectedValue(theta); for(int m=0;m<irm.getNcat();m++){ Wni += Math.pow(m-Eni, 2)*irm.probability(theta, m); } return Wni; } RaschFitStatistics(); void increment(ItemResponseModel irm, double theta, byte Xni); double getUnweightedMeanSquare(); double getWeightedMeanSquare(); double getStandardizedWeightedMeanSquare(); double getStandardizedUnweightedMeanSquare(); double varianceOfResponse(ItemResponseModel irm, double theta); double kurtosisOfResponse(ItemResponseModel irm, double theta); public double Z2niSum; public double WniZ2niSum; public double WniSum; public double umsNumeratorSum; public double wmsNumeratorSum; }### Answer:
@Test public void informationTest(){ System.out.println("Testing item informaiton in RaschFitstatistics"); Irm3PL rasch = new Irm3PL(0.0, 1.0); RaschFitStatistics fit = new RaschFitStatistics(); NormalQuadratureRule norm = new NormalQuadratureRule(-4.0, 4.0, 150); double[] theta = norm.getPoints(); for(int i=0;i<theta.length;i++){ double v1 = fit.varianceOfResponse(rasch, theta[i]); double v2 = rasch.itemInformationAt(theta[i]); assertEquals("Testing information", v2, v1, 1e-15); } }