private string ChooseAttribute(DataSet ds, IList <string> attributeNames) { double greatestGain = 0.0; string attributeWithGreatestGain = attributeNames[0]; foreach (string attr in attributeNames) { double gain = ds.CalculateGainFor(attr); if (gain > greatestGain) { greatestGain = gain; attributeWithGreatestGain = attr; } } return(attributeWithGreatestGain); }