First Nielsen Media Research selects the area to be surveyed. This is a decision of the station or stations within the market. Normally, the markets service (licence) area is used. Once the total area is known, the population for each Statistical Local Area (SLA) within the total area is estimated. Using Hobart as an example, the SLA of Glenorchy represents 20.4% of the total area. Therefore approximately 20.4% of the diaries will be placed in Glenorchy. The diaries are placed proportionally to the population within each SLA. The number of occupied private dwellings is also taken into account.

The size of the sample is not directly related to the population of the area to be surveyed, but rather to the demographics that need to be reported. For example, if a station only requires men and women 10-24, 25-39 and 40+ to be reported, a sample of 400 people would be sufficient. However, if much finer demographics are required the sample would need to be larger.

The size of the sample also depends on the complexity of the market and the size of the area being surveyed. Substantially larger samples are needed in the major cities because of the number of stations that can be heard and the wide geographic spread of the service areas.

A number of interviewing areas are chosen throughout the area (in proportion to the population of each of the SLA's) and maps are drawn of each of these areas.

Interviewers are given maps of the interviewing areas and a "starting point" where placement must begin. At each selected house, the person answering is asked whether members of the household would participate in the survey. If so one diary is left for each person aged 10 and above.

If nobody is home, two more attempts must be made. This keeps the random sample as pure as possible. Records are kept of any refusals, so that these levels can be carefully monitored.

Details regarding the household are recorded on a "Household Record Form". Characteristics of the respondents, such as sex, age, gross income, occupation and language spoken are collected.

Each person within the household is asked to record their listening in a "diary of listening" for a one week period. A Lifestyle Questionnaire which lists product usage and intention to buy is also completed.

Once collected, entries in the diaries are carefully checked by experienced Field Supervisors and Coders. Coded diaries are sent to Data Entry and from that point are processed to produce final figures. Before final processing, a "weighting" or raising factor is employed, which ensures that the results can be projected to the proper proportions of the population.