Unlike earlier religious revivals based on powerful preaching, the revival of 1904-05 relied primarily on music and on alleged supernatural phenomena as exemplified by the visions of Evan Roberts.
The after effects of the revival were considered by Vyrynwy Morgan in the final chapter of his book gives the figures for convictions for drunkenness in the county of Glamorgan for the years 1902 to 1907, supplied by the police.