What is TDI in Market Research?

Alexander Graham Bell debuted the first functional telephone in 1876. However, the foundation for his invention started more than 25 years prior and incorporated the works of nearly ten other innovators racing to connect people over time and space. With the eventual widespread use of telephones and other telecommunications devices, the world has expanded and paradoxically condensed in equal measures: Never have we, as humans, been more aware of our connectedness while remaining mindful of our separateness. Today, the telephone is an omnipresent reality that spans miles, relaying information instantaneously and uniting us even as we live scattered and independent lives.

In the market research world, the telephone can be a double-edged sword. Yes, it provides a relatively easy way to interface with consumers, linking people who might not otherwise be able to share their thoughts due to physical restraints. But it can also impede a researcher’s understanding of data by prohibiting him or her from capturing critical non-verbal cues that can manifest during face-to-face interviews. The aforementioned insulation and isolation of people (and, in this case, consumers) make meaningful relationships hard to foster.

Telephone depth interviewing (TDI) can alleviate some of the problems with simple telephone (not depth) interviewing by extending and enriching the time an interviewer spends talking to an interviewee, thus deepening the scope of information gleaned.

The Who

Put simply, TDI market research is a qualitative research method that uses one skilled interviewer to communicate with one respondent over the telephone.

The What

The intimate setting of TDI market research allows for a comprehensive exploration of a respondent’s experiences and knowledge, as well as his or her motives and perceptions. Companies usually conduct 12 to 60 interviews, each lasting anywhere from 30 to 90 minutes depending on the issue at hand.

The When

Companies frequently choose in-depth interviewing when respondents might be embarrassed to share their opinions in a group setting, when they want expert opinions, when they have sensitive or confidential material to review or when the logistics of a larger gathering are prohibitive in some way (cost, location, transport, etc.).

The Where

Anywhere! Telephones are universal.

The Why

In addition to providing increased rapport and flexibility, TDI market research also frequently saves companies money. It costs less than conducting focus groups because there are no travel, accommodation or catering costs. And it often provides more meaningful data. For instance, a focus group has an average of 10 people. If the session lasts two hours, each person only has an average of 12 minutes to speak. It’s even less than that if you consider that the moderator will do some of the talking him/herself.  Compare that to the 30-90 minutes a telephone depth interviewee spends talking to the moderator. Even if the interviewers spends 20% of the time asking questions, that still leaves 24-72 minutes for the respondent to reflect and give valuable information. Having additional time per person to flesh out responses can often mean more (and better) insights.

Learn More

The telephone can be a valuable tool for researchers in a tight economy or under a strict budget. It allows for robust data mining when other methodologies just won’t suffice. At Communications for Research (CFR) we understand when and how to make use of TDI market research and can help you decide what’s best for you. Contact us for more information.

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