def extract_coordinates(user_information):
    """
    Extracts the turker's coordinates: (latitude, longitude)
    Args:
        user_information: dict with the user information of the turkers (returned from @extract_information_per_turker
    Returns:
        locations: latitude, longitude) pairs
    """
    coordinates = []
    for turker_id in user_information.keys():
        latitude = user_information[turker_id]['latitude']
        longitude = user_information[turker_id]['longitude']
        coordinates.append((latitude, longitude))
    return coordinates