@SuppressWarnings("unchecked")
	@Override
	public double getScore(Object userAnswer) {
		if (userAnswer == null)
			return 0;
		ArrayList<String> ans = (ArrayList<String>) userAnswer;
		ArrayList<String> trueAns = (ArrayList<String>) answer;
		ArrayList<String> ques = (ArrayList<String>) question;		
		int matches = 0;
		for (int i = 0; i < ans.size(); i++) {
			for (int j = 0; j < trueAns.size(); j++) {
				if (ans.get(i).equals(trueAns.get(j))) {
					matches++;
					break;
				}
			}
		}
		return score * ((ques.size()-1) - ans.size() - trueAns.size() + 2*matches) / (ques.size()-1);
	}