def check_valid_column(observation):
    """
        Validates that our observation only has valid columns

        Returns:
        - assertion value: True if all provided columns are valid, False otherwise
        - error message: empty if all provided columns are valid, False otherwise
    """

    valid_columns = {"observation_id","Type", "Date","Part of a policing operation", "Latitude", "Longitude", "Gender", "Legislation", "Object of search", "Age range", "Officer-defined ethnicity", "station"}

    keys = set(observation.keys())

    if len(valid_columns - keys) > 0:
        missing = valid_columns - keys
        error = "Missing columns: {}".format(missing)
        return False, error

    if len(keys - valid_columns) > 0:
        extra = keys - valid_columns
        error = "Unrecognized columns provided: {}".format(extra)
        return False, error

    if len(keys - valid_columns) == 0:
        return True, ""