public TrialGroup(List<Trial> trials, boolean lowLoad) throws IncorrectNumberOfTrialsException {
		super(trials);
		if (trials.size() != Options.TRIALS_PER_GROUP) {
			//should not occur
			throw new IncorrectNumberOfTrialsException("Trying to create a group of " + Options.TRIALS_PER_GROUP + " trials, but only " 
					+ trials.size() + " were passed to the constructor!");
		} else {			
			for (int i = 0; i < trials.size(); i++) {
				trials.get(i).indexInTrialGroup = i;
			}
			
			if (lowLoad) {
				pattern = new LowloadPattern();
			} else {
				pattern = new HighloadPattern();
			}
		}
		
	}