Ask TON: How Many Interviews?

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Welcome back for another installment of Ask TON. Here’s our latest question:

For a typical mid-length feature story, how many interviews would you typically do, and how long would each one typically last?

Erik Vance, freelance science journalist:

Of course, there’s no real way to answer this. I was told once that you should quote about 30 percent of the people you talk to. That way, you always talk to more than three times the number of people than you quote. Generally, that feels right but of course it might be far too many people for a short piece and far too few for a long one.

Someone else told me that as soon as you start hearing the same answers from different people, you have talked to enough people. This also feels right but it could mean that you are talking to people who are just being safe or that your interview pool is not diverse. On occasion, if you’re creative, you’ll find gems long after most people start sounding alike.

The important thing is that you know a lot more than what you write—that you have the context that will never make it into the story because it’s far too boring. I’ll even tell sources once we’ve wandered into background, non-story territory. Mostly, they don’t care and are impressed that I’m interested in the details. The lengths of the interviews vary. I usually say half an hour, but that often stretches to an hour. Too much more than an hour and you should split it into two interviews separated by some time to think. But, especially with difficult interviews to secure, take as much as you can get—it will always broaden your understanding.

However, these rules don’t apply to practicing doctors. If you are talking time that a doctor could be using to treat patients, ask yourself, “is this worth it?” With politicians, you are encouraged to waste as much of their time as you can since their job has far less impact on society.

Genevive Bjorn, freelance science journalist:

By mid-length I’m guessing you mean around 1,000 to 1,200 words. That’s what I’ll answer around. The number of interviews depends on a few key factors: the complexity of the topic, my deadline length, and my level of background knowledge. Three interviews is my absolute minimum, representing different points of view, for any story. If I’m a newbie to the subject or it’s a complex story, I’ve done upwards of a dozen interviews. Looking back over my work in recent years, where I’ve had at least one week to deadline and am familiar with the subject matter, I average 4-6 interviews per medium length story.

Jeff HechtNew Scientist contributor and freelance science and technology writer:

The short answer is that it varies, which you probably have heard from just about everyone who isn’t subject to rigid requirements by the editors.

Because of the way I organize my interview notes, I can give some approximate numbers:

  • For a short dinosaur feature for New Scientist: five, typically lasting 30 minutes
  • For a short feature for a laser magazine on nonlethal laser weapons: five, each typically lasting 15–30 minutes.
  • For a longer feature for New Scientist on “missing links”: ten (not counting one or two at a conference), ranging from 15–45 minutes.
  • For another short laser feature: four, each 15–30 minutes.
  • For a feature for New Scientist on LED lighting: 10, lasting from 15-45 minutes.

Where I need to do a lot of exploring, I often conduct 10-12 interviews, and typically interviews last 30 minutes on the phone. If the story centers on a few key people, interviews with them can run an hour, and sometimes I go back to them a second time.  If I have already done some leg work, or am covering work done by one group, I may only talk with 4 or 5 people.

The laser magazine features are different because I was trained as an engineer and have covered the technology for decades, so I can read and comprehend much of the literature. My writing ranges from a review of the recent literature to a more conventional feature with multiple sources, depending on the subject and the sources whom I can reach in the time available.  I try to talk with two to four people for a half-hour each, but that doesn’t always work. One problem is the limited number of possible sources on some of the specialized topics I cover. Time zone logistics and language problems are major issues, because much—and sometimes nearly all—work on some topics is done in Asia. I contact sources in non-English-speaking overseas countries by email, and most in Asia prefer to respond by email rather than do an oral interview. Some do not respond at all.

Jill Adams, science and health writer:

My response will not satisfy anyone: It depends. Length is one part of it, of course. The longer a story is, the more angles to visit.  Each angle is another opportunity to include a voice. It also depends on the story itself, such as what the driving questions are, how controversial the topic is, and who the main characters are.

Knowing that the questioner here is looking for a rule of thumb—and knowing that I myself have posed this question in the past—I’ll provide one. I am a master of 800- to 1,000-word news articles and my magic number is three. On the health beat, that might mean an epidemiologist who co-authored a study that says diet soda causes weight gain, a prominent obesity research to give broader context, and a physician who sees patients whose weight contributes to their disease. Often enough, I call a fourth source and sometimes five or six. I may not always quote each person, but I need to talk to enough people to feel I’m on solid ground.

If a “mid-length feature story” is twice that length, you might figure on six sources as a starting point. However, a 2,000-word story is not simply two 1,000-word articles sewn together. You have more opportunities to explore different facets, so your sourcing will depend even more on the story’s demands. In a story with a prominent main character, you might want a couple of outside voices to comment on the science and a couple of colleagues to comment on the person. In a story surveying recent progress in a scientific field, you might need to talk to several of the primary researchers and be asking them to talk about each others’ work. And you’ll still need an outside voice, perhaps a scientist who’s spent decades in the field to contribute the long view to your story. In a story about a controversial topic, you may well have to double the number of people you talk to, so you can report the topic with some authority and be less susceptible to experts’ often-convincing perspectives.

As for how long interviews last, guess what?  It depends. If you’re visiting a source in person, it might be an hour or all day. For phone interviews, I’ll give you my rule of thumb: 20–30 minutes. That’s my standard email request. Mostly because that’s about all I can handle at one time. I need mulling time to digest what I’ve been told and to think about how that information will fit into my story. You may need to talk to a source more than once, of course.


Image by Venus Wu via Flickr.

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