public boolean add(Topic topic) {
  		if (topic == null) {
  			return false;
  		}

  		if (!contains(topic)) {
  			InterestListElem newElem = new InterestListElem(topic);
+ // newElem weight muss auf 1 gesetzt werden
+ // -0.5p

  			if (first != null) {
  				newElem.setNext(first);
  			}
  			first = newElem;

  			return true;
  		} else {
  			find(topic).increaseWeight(1);
  			return false;
  		}
  	}