Those seeking to replicate historic Barb programme figures via contemporary analysis tools should bear in mind that a number of factors may mean figures do not match exactly. These include, but are not limited to: changes to data included in logs by companies that submit broadcast logs, the advent of +1 channels, the inclusion of HD viewing with SD viewing to a channel, changes to the definition of the viewing day, log amendments, data re-issues and the addition of viewing from PCs, tablets and smartphones (September 2018).