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The RADAR® service provides a national measurement of radio listening and network audiences. Reports are issued four times a year. The study is based on a probability sample of more than 225,000 respondents, aged 12 and older.
These reports are designed to provide estimates of national radio usage and network radio commercial audience during an average week within the United States. The estimates are derived from listening information from Persons 12 years of age and older living in the United States, excluding Alaska and Hawaii (based on Arbitron radio market reports for Diary and PPM™ methodologies; See the RADAR Reference Guide for more information.
For local market surveys, Arbitron samples are allocated to optimize the measurement of each market. This means that Arbitron’s sample sizes are disproportionately allocated relative to the national population. The system developed to select the respondents to be used in RADAR is designed to efficiently draw a nationally representative subsample from Arbitron’s local market samples.
Each RADAR report represents four quarters. During the course of one year, a RADAR sample is drawn from each of the four Arbitron surveys: Winter, Spring, Summer and Fall. (For the Winter and Summer surveys, when not all counties are measured, the respondent base for the 97 continuously measured markets is supplemented by the respondent base from the Spring or Fall survey immediately preceding.)
Each of these RADAR samples is drawn with probability proportional to the size of the population, using the weights that were created in producing the original Arbitron local market reports. This means that the sample can be used as a national sample on an unweighted basis, although Arbitron will continue to sample balance the respondent database.
To prepare Network Radio Audience estimates, usage information is merged with clearance data for broadcasts and commercial exposures. That is, quarter-hours of radio usage, as reported by respondents, are matched with program and commercial clearances provided by the radio networks for each station carrying such programming.
Clearance data used for this purpose are network-affiliated stations for one week per report and program and commercial clearances for two selected weeks in the most recent year. Affiliated stations supply clearance affidavits to the networks. Networks process these data and report to Arbitron.
For each broadcast, the network designates the number of commercial units. For each commercial unit in each broadcast on each station, the network reports the commercial unit was cleared within the program at a specified time, or the commercial unit was extracted from the program and carried at a specified time, or the commercial unit was not carried at all.
Data ProcessingArbitron randomly selects one commercial unit from each broadcast, and audience is calculated based upon the carriage day and time for that specific commercial unit. If a person reported listening to a station during a quarter-hour in which a network program or commercial was cleared, then the person is considered to be in the audience for that program or commercial.
A discrepancy between reported clearances and the results of verification may mean the reported program or commercial was played at a different time, or possibly not at all. In any case, any discrepancy is counted as an error in computing a clearance accuracy rate. Overall network results are provided to all clients each quarter, including a rolling average of four quarterly reports, plus the most recent quarter. Each network organization receives a report on the results of the monitoring efforts for its own clearances.
Arbitron uses Mediaguide and Media MonitorsSM broadcast monitoring technology to verify whether the radio commercials that were scheduled to be aired on affiliated stations of RADAR-rated networks were broadcast as indicated in the network commercial clearance reports. Arbitron will monitor 2400 stations in 2008. The stations are monitored for 3 to 5 hours over the course of a week, depending on their network affiliation.
The Media Rating Council® grants accreditation to ratings services based on specific criteria that are independently audited by the accounting firm of Ernst & Young, following specified procedures. Based on audit results, RADAR has been an MRC-accredited audience measurement service since 1974.
PPM™ and RADAR® are marks of Arbitron Inc. Media Rating Council® and the “double checkmark” logo design are registered trademarks of the Media Rating Council. Media MonitorsSM is a service mark of Media Monitors, LLC.
Last updated: 5.7.08