@Override
	public double calculateAgreement() {
		double D_O = calculateObservedDisagreement();
		double D_E = calculateExpectedDisagreement();
		if (D_O == D_E)
			return 0.0;
		else
			return 1.0 - (D_O / D_E);
	}
@ Override public double calculateAgreement ( ) { double D_O = calculateObservedDisagreement ( ) ; double D_E = calculateExpectedDisagreement ( ) ; if ( D_O == D_E ) return 0.0 ; else return 1.0 - ( D_O / D_E ) ; }
/* Calculates the inter-rater agreement for the annotation
study that was passed to the class constructor and the currently
assigned distance function.
@throws NullPointerException if the study is null.
@throws ArithmeticException if the study does not contain any item or
the number of raters is smaller than 2.