def compare_results(s1, s2):
    """Compares two sets.
    
    Arguments:
        s1: set, first set for comparison.
        s2: set, first set for comparison.
    
    Returns:
        dict, data with comparison results for sets.
    """
    data = {}
    data['common'] = s1.intersection(s2)
    data['missing'] = s1.difference(s2)
    data['extra'] = s2.difference(s1)

    return data