Percentage of selected audience which is tuned to a particular medium at a given time, e.g. the proportion of the target group who are watching a particular TV channel between the hours of 7:30 p.m. and 8:00 p.m.

The number of persons who listened to a station during a given time period, expressed as a percent of all persons who listened to radio during that time period. Many people confuse ratings with shares since both are shown as percentages. A rating always relates to a total population (e.g. Census Data), whereas audience "share" always is expressed in terms of the total listening/viewing activity taking place during a particular time period.

The percentage of the total audience in a specific time period tuned to a particular station or program; frequently referred to as "share."