CASE STUDY 9/98

Telephone-based market research - apparent disclosure of unlisted telephone number

The complainant received a phone call from a market research company carrying out a survey. As his telephone number is ex-directory, the complainant asked how this had been obtained. He was given to understand that his phone number had been obtained from the telephone service provider. When the complainant visited the offices of the telephone service provider to protest about the apparent disclosure of his unlisted number, the provider stated unequivocally that it did not disclose unlisted telephone numbers to third parties. The complainant raised the matter with my Office, saying he was disturbed that his unlisted telephone number had become available to the market research company.

In the course of my investigation, I contacted the market research company to ascertain the source of the telephone numbers which had been used. The market research company explained that it had been contracted by a client company to undertake a continuous survey, which involved contacting a representative sample of the population every four weeks. To achieve this objective, a system of random number dialling was employed whereby a telephone number was taken from the public telephone directory, and then used to generate random telephone numbers by simply adding or subtracting a number. The number initially selected from the directory was not dialled. The market research company informed me that this method of random generation of telephone numbers meant that unlisted numbers and also fax numbers were called from time to time. The company said that it had not been supplied with any ex-directory listings or other personal data by the telephone service provider. Moreover, the company’s interviewers did not ask either the names or addresses of the interviewees. Only the answers to the questions which were put to the interviewees were recorded for research purposes. Accordingly, the anonymity of the respondents was not in any way compromised.

A member of my staff visited the offices of the market research company to investigate at first-hand the nature of the processing undertaken by the company. The results of this inspection were consistent with the market research company’s account of its activities.

Given the facts that came to light in the course of the investigation, and the lack of any evidence that the complainant’s unlisted telephone number had been disclosed by the telephone service company, I did not uphold the complaint.