Sampling - The key element of inquiry

Vida Srot
Radio Slovenia, Slovenia

1. PREFACE

From 1980 to 1993 the Research Department of Radio Slovenia, in a country with two million inhabitants, researched radio listening with personal interviews and postal inquiries. The results obtained confirmed that people tuned into the radio for 151 to 246 minutes per day. When carrying out the same research between December 1994 and April 1995, the data showed only 137 to 119 minutes of listening per day. Discussing the results with data users we state that the amount of time spent listening to the radio has not changed considerably over the past year. What is the evidence to support this statement?

The Research Department of Radio Slovenia carried out its research methods identically in both periods: all new data is new due to the particular date of collecting. Usually, we get data about the same facts collected with the same methods but in different time periods, or the methods are altered but the time period remains the same. In Slovenia there are three national, two regional, and 20 local, public radio stations: during 1994 they were joined by 20 commercial radio stations, mainly broadcasting pop music and talk shows (the range of audibility is between the local and regional range). After the political changes in Slovenia interest for informative and political programmes, broadcasted mostly by the national station, fell considerably. Listeners tune to music programmes more and more, especially to the new commercial stations. While listening to the music programmes, they are not necessarily as concentrated as they are during the talk programmes. Recollection and receptivity of the music programmes are poorer than the receptivity of talk programmes. For this reason, we maintain that the respondents were tuned to the radio stations for approximately the same amount of time as in the past, only they filled-in less data and they encircled fewer time interval codes on our forms.