There’s an old saying in marketing circles that your customer can tell you everything you need to know — if you ask the right questions.

When you’re doing customer research to plan or assess the effectiveness of your marketing campaign, it helps to know what to listen for — and how to steer a conversation to get to the important stuff.

There’s a wealth of information to be had talking to people one-on-one. You can’t glean the same kind of insights from focus groups. People tend to “play act” in focus groups. They often mask their true feelings in order to impress others.

Unfortunately, the best one-on-one interviews with customers and prospects can’t be fully scripted because different individuals react to questions in different ways. They hear what they want to hear — and often not what you think you’re asking. A good interviewer has to be flexible and be able to steer the conversation back to the points the need to be covered. It’s a skill that some people have — and lots of people don’t. So you want the right kind of people asking the questions and doing the listening — people who can be flexible, think on their feet, and “read” others.

Finally, be sure to observe your customers and prospects in their natural surroundings, so they feel more at ease. If you’re taste testing beer, for example, go to bar. If you’re researching the benefits of a new credit card, do it in a shopping mall. One of the reasons why focus groups don’t usually give you the kind of valuable insights you need — and end up being merely “role playing” exercises — is because they are held In sterile rooms with one-way see-through windows.  People in unnatural surroundings tend to respond accordingly.

Qualitative interviewing is more art than science, but the insights it can yield can be invaluable. Some of the most effective marketing campaigns in history grew out of insights gleaned from one-on-one interviews. Maybe your next campaign can be one of them.