In economics there is a term known as “sunk cost.” Investopedia defines a sunk cost as, “A cost that has already been incurred and thus cannot be recovered.” A cost does not have to be monetary either; it can be thought of in terms of time, resources, or anything else of value to a company. Business decisions are made independent of sunk costs. At first glance, this may seem a little ridiculous. If you have put hundreds of hours or thousands of dollars into a project, then you should work tirelessly to make it succeed, right? Well, the brutal reality is that sometimes we just have to accept that a project has gone bad, and it is time to move on. It can be best to just cut your losses and not lose any more money.
This idea of sunk costs applies to market research interviews (or in-depth interviews, IDIs) as well. As does the concept of knowing when to walk away.
In-depth interviews can be an immensely valuable research methodology, and many market researchers use this tried-and-true approach (see some of the reasons why in this article from Quirk’s Marketing Research Review). But when conducting IDI research, a lot of time goes into planning before the actual interview is conducted.
Once a firm has spent all kinds of money and devoted countless hours to developing the IDI guide and screening participants, they should not waste a single opportunity right? Shouldn’t every scheduled IDI be completed fully? Not always: money and time at this point is a sunk cost. The goal now is to conduct as many good in-depth interviews as possible. Wasting time on a bad interview just frustrates the interviewer and wastes time that could be better used elsewhere, so why bother? Unfortunately, in the quest to meet sample size goals and “not waste” sunk costs, too many researchers end up completing bad interviews.
So here is the critical question: how does one determine what is a bad interview and what is not? How long into an interview is it before it is possible to tell it is not worthwhile? What is the best way to end a bad interview? Each interview will be different and you will have to make a judgment call, however, Research Rockstar’s class on Conducting Research Interviews can provide you some valuable guidelines and tips for handling these unfortunate situations.[Want to learn 12 valuable steps for stress free interviewing? Visit Research Rockstar and take their self-paced, online class on Conducting Research Interviews. This class is available as both a self-paced and an instructor-led format: click here for dates!]