Two of the channels, BBC Three and BBC Four, "barely appear on the radar screen for viewers. It is not helpful for two of the BBC's channels to be so small," said Patrick Barwise, a professor who serves as an adviser to Culture Secretary Tessa Jowell, the Times of London reported Thursday.
Barwise suggested the BBC revise its strategy of courting targeted audiences, such as youth, in favor of appealing to the general audience.
The professor's findings come after a six month study of BBC Three, BBC Four, CBeebies and CBBC, digital channels costing public license payers more than $235 million.
BBC Three has a 0.7 percent share of viewing in digital homes, even though it has a programming budget of approximately $175 million, more than most digital channels.
BBC Four, with 0.3 percent of viewers in its first 2 1/2 years, was criticized for "showing arts and other programs that virtually nobody watches," Barwise said.