Avoiding liturgies and all elaboration that might interfere with the direct guidance of the Holy Spirit, the Friends often meet for worship without set form and frequently without stated leaders, in services known as "unprogrammed" meetings. Any member is at liberty to follow the impulse of the spirit in prayer, praise, or exhortation. A meeting may be spent entirely in silent receptivity and communion. A "programmed" meeting may have some form of ceremonial order. Ministers are not required to have special training; any man or woman who experiences the call to the work and gives evidence of sincerity and ability may be recorded as a minister. In more recent years, however, many of the Friends who seek the ministry have studied at theological schools.