When Should I Use One-on-One Interviews Over A Survey?

The 1,2,3’s Of Knowing When to Use Qualitative Over Quantitative Research

In countless meetings and conference calls to discuss potential research projects, one of the most common questions I receive is, “Should I do focus groups or a survey for this project?” or, “Are interviews better than focus groups?”

The right answer isn’t always clear. Even after performing research for nearly 20 years, more questions nearly always precede my answer.

First, I will add that many studies in fact combine qualitative and quantitative techniques, and combining them should be used more often than they are in practice. More importantly, there are reasons for using them in varying order (qual-then-quant versus quant-then-qual). We will discuss this in a later article.

Often, research efforts will just not justify a lofty enough budget to perform both methods, and as a result, it becomes important to choose one component of the research and invest all of the available resources in that study. Sadly, this happens, but sometimes it is unavoidable, as either there are not enough respondents to project to the audience at large, or in many cases, it is less costly to tolerate the risk than to conduct the second leg of the research. 

In my experience, the answer to the question regarding “What research technique should I use?” centers around the answers to the following set of questions:

  1. Can you provide a list of potential answers to each question you would like to ask your audience? Do you think you know most of the important potential answers?
  1. Is there a story you are looking for, or a narrative to a set of circumstances or events?
  1. Are you seeking to describe behavior across a large population? Is “statistical significance” an essential requirement of the research?


Qualitative research is a critical competency for any company’s product development and marketing processes. Since it is indispensable, it needs to be conducted by either qualified professional market researchers, or well-trained, experienced, internal team members. As we begin this discussion, it is important to recognize this is only offered as a guide to recognize qualitative vs. quantitative research projects from a macro perspective.   


Can you provide a list of potential answers to each question you would like to ask your audience? Do you think you know most of the important potential answers? 

Sometimes, when researching a topic, you may know the general questions you would like to ask of your audience, but you do not know the range of answers you may receive, or which of these are likely to come up most often. If this is the case for you, an exploratory qualitative research study is right for you.

The good news here is, it is usually fairly easy to know when this method is best: when you can’t easily think of the answers yourself to the questions you would like to pose, or when convening a group of your peers internal to your department unearths little more. At best, there may be answers, but there is little agreement as to the range of options.


Is there a story you are looking for, or a narrative to a set of circumstances or events? 

You may be looking to hear more about a decision-making pathway, a customer journey, or a series of events in the lives of your customers. In these cases, a survey is a very challenging tool to use.

It may be difficult to expose all of the optional outcomes that were possible at each important juncture, a requirement for the use of a survey to gather this information. This is when the qualitative interview shines; in opportunities to hear and probe on stories or narratives.


Persona Research is an Excellent Example


We recently finished a series on persona development, including definitions and an approach to articulating the personas required for a given audience.

In this case, while segmentation research is very useful in the leadup to developing personas, the critical intelligence involves a narrative or story. This is extremely difficult to articulate in a survey, beyond verifying consistency of a pattern observed in the persona interviews. Therefore, if you are looking to gather story components and stitch together narratives for different personas, or individuals, or for different product use cases, the qualitative study is for you.


Are you seeking to describe behavior across a larger population? Is “statistical significance” an important proof source for your research results?

In the case of ensuring a research result is projectable to the population at large, it is important to say most research is meant to understand behaviors of a group or segment of a population through “sampling” or debriefing a small group of respondents that represents the larger group. Sometimes, however, this is an imperative. It is required by senior leadership, or by an internal gating process.

In these cases, you need a survey. Right?


But what if you don’t know enough to write a survey, yet still need statistically significant results?

More than likely, your research will be a two-step process. Ensuring you have statistically significant results will require you to set up your research more formally, and decide more carefully on how many respondents you sample in each subgroup you need to describe. This means that if you have three groups and you need to know how each behaves independently of each other, you need a large enough sample for each group to detect these differences. If you are seeking to describe the differences in behaviors between the three group, then you can get away with a smaller sample overall. 

Sidestepping all of the details surrounding why (it is not too complex a problem, but beyond the scope of this article) statistical significance is usually attained through larger samples of respondents than is practical for qualitative, discussion-oriented studies. But investing in even a very short series of one-on-one interviews prior to fielding a survey offers important advantages which will yield much more complete and reliable quantitative research.

Need help with deciding how to do your next research project? Let Actionable Research offer you some experienced-grounded assistance. We’ll be happy to discuss your research goals and identify the a cost-effective solution that will provide you with Actionable results.

Get Your Free Whitepaper Today