Other questions have been raised about diary-based data collection methods. The expectation that diarists participating in the radio sample will accurately record their listening at 15-minute intervals has been challenged by many analysts. Many analysts suspect that diarists only fill in their diaries at the end of each week, or perhaps less often which forces them to recall their radio usage thereby raising concerns about reliability. In addition the diary based method appears to inflate average audience size, because the total audience is captured by recording any person who was listening during a quarter-hour counts as listening for the entire duration, even if the actual time was just for a minute or two.