REACTIVE EFFECTS OF A SURVEY ON THE TELEVISION VIEWING BEHAVIOR OF A TELEMETRIC TELEVISION AUDIENCE PANEL - A COMBINED TIME-SERIES AND CONTROL-GROUP ANALYSIS

Data from telemetric television audience panels are invaluable for com mercial and scientific television research For the study of most resea rch questions, however; it is necessary to request additional informat ion from the panel participants. Such interventions can only be permit ted if they do not threaten the validity of the telemetric data. This study investigates whether a questionnaire intervention disrupts the v iewing behavior of a television audience panel. The results indicate t hat, on the day they completed a questionnaire, experimental subjects watched a small amount more television than controls who received no q uestionnaire. It is argued that such a small effect on one day should not be accorded practical relevance. In addition, the article introduc es a combined time-series and control-group design with which interven tion-effect hypotheses can be investigated. It is suggested and illust rated that this design has a number of important advantages over tradi tional approaches.