if( this.propertyEvaluation == null ) {
propertyEvaluation = new PropertyEvaluation( this.getProperty().getUri() );
}
// If not set, default to the equivalence from the measurement.
if( propertyEvaluation.getUserEquivalence() == null ) {
Equivalence eqv = this.getEquivalence();
if( eqv == Equivalence.EQUAL ) {
propertyEvaluation.setUserEquivalence( EquivalenceStatement.EQUAL );
} else if( eqv == Equivalence.DIFFERENT ) {
propertyEvaluation.setUserEquivalence( EquivalenceStatement.DIFFERENT );
} else if( eqv == Equivalence.MISSING ) {