Should You Do Focus Groups or One-on-One Interviews?

Having Trouble Deciding? Here are 5 Key Points to Consider.

If you have been involved in either commissioning or executing qualitative research, the question has almost certainly come up: Should we do focus groups or one-on-one interviews? Below are the 5 most important questions to answer before you make your decision.  For this brief, we will refer to one-on-one interviews as “In-Depth Interviews” or IDIs for short.


What are the Differences Between Focus Groups and IDIs?

In order to make the decision on which direction to go, it is important to first understand the differences between the two modes of research.  For some this will be a basic review, but it is essential to understand their definitions before we can understand the dynamics, opportunities and drawbacks of each approach.

Focus groups involve a group of research participants that can range from two, three, or anywhere between 4 and 12 participants and can be performed either in-person or, under certain circumstances, online. There are specific situations where qualitative-style feedback can be gathered using “Supergroups” larger in size than 12 participants, but most qualitative researchers will stop at 12 and would agree they are best when between 6 and 8 participants. How many participants you may choose to have in each group will be dependent upon the group participant type, the core goals of the research and the subject matter. 

An IDI is a one-on-one interview with the interviewer and the interviewee. IDIs are typically between 20 minutes and an hour in length, although longer sessions can be fruitful depending on the potential tasks that may be required of the interviewee. IDIs are performed in person, online with telephone support or via telephone only, again depending on the subject matter being covered. In-person interviews are required when it is necessary for an interviewee to touch or try out a product or product concept, or in situations where it is important to gather non-verbal cues. IDIs can also be supported via screen sharing technologies like WebEx, GoToMeeting, Lync, etc. when an evaluation of visual stimuli is required. 

I speak to clients who are frequently considering either focus groups or IDIs as alternatives for their project. In most cases, there is a best way to go, and the following 5 factors nearly always offer clarity concerning which is the best choice.

Before getting started, I will say there are unique situations where both options are equally effective, and there are some special cases where I strongly advocate a mix of both that I will address at the end. Also, for the purpose of this discussion, I am going to address focus groups as an in-person phenomenon, as online groups are often limited in their applicability both audience-wise and in their inability to adequately engage respondents in their current form.


Question 1: Is it important to obtain a geographically representative sample?

While qualitative research is directional in nature and doesn’t actually “represent” a population in the way quantitative research does, it is just as important to balance a qualitative sample as it is for quantitative research. Frequently, it is important to gather a geographically representative sample of qualitative participants or interviewees to adequately answer a research question.  In these cases, the researcher would be more likely to choose IDIs, and perform them in either a telephone or online format.  While many of the non-verbal cues are lost using telephone, facial expressions and reactions are able to be captured using online IDIs with webcam support.

The same goes for many international efforts.  Budgetary constraints can make in-person qualitative research prohibitively expensive, and for a good percentage of these projects, it is possible to perform a series of telephone IDIs in the native languages of the audiences at a fraction of the cost. Research involving clinicians and professionals can be efficiently performed in this manner; however it is critical to ensure both interviewers and the designers of the research have an adequate understanding of the local markets under study.


Question 2: How would your research participants react to being in the same room together?

This is an important consideration that is sometimes missed early on in the consideration stage of the research. Bringing together a group of 18-30 year olds to discuss computer gaming is not problematic in this regard, however bringing together 6 hospital administrators in the same market is a different matter.  If strategic decision-making or sensitive subject matter is being discussed, it will likely be challenging to get candid answers from a group of executives if they feel they could be giving something away to their peers.  Competitors asked to share their thoughts in each other’s presence is not likely to be an effective means of gathering thoughts and opinions on how they could make use of your products or services.

In this case, IDIs are almost always the way to go.  In those unique situations where the subject matter is light or if discussions of policy or market environment are most important, groups could work. Yet, substantial risk still remains.


Question 3: Is peer-to-peer interaction an important consideration for your research question?

Qualitative research is typically about exploration, and at times the focus of that exploration is how your audience members react to each other’s ideas or opinions.  If peer-to-peer reaction to ideas and/or concepts are important objectives for discovery in your research, it is most likely best to use a group format.  While the other group-oriented constraints still apply from Factors 1 and 2, a requirement to drive peer-to-peer interactions and/or understand which types of individuals are most influential concerning your product or service may tip the scale in favor of groups when other detrimental factors are deemed to be mild (competitive clinicians in the same geographical market for example).

There are other situations where peer to peer interactions can be destructive.  In situations where participants may be reticent to talk amongst their peers about the desirability of a particular product or service (for example, men considering plastic surgery procedures), it can be very difficult to moderate these kinds of issues out of a group; IDIs can offer richer, more candid feedback. Sometimes, even with the most experienced moderators, statements from influential group members can poison a group irreparably. 

There are ways to simulate peer-to-peer reactions in IDI environments in some situations.  We will discuss this topic in a future article.


Question 4: Do you need to understand how your product or service claims, features and/or benefits compare relative to each other?

Concept testing comes in all shapes and sizes, and in certain instances, the concept under test is not the main subject of the research effort.  This happens in earlier stage exploratory research or in situations where the focus is insight gathering.

For other projects, the main star of the event is the product or service concept.  In these situations, it is frequently very beneficial to have the feedback that comes from a group.  While these questions can be asked and effectively answered using an IDI format, a group format offers the ability to receive both initial reactions unaffected by other group member opinions as well as a discussion-oriented look at claims, features and benefits after being colored by other participants.


Question 5: Do you need to find a minimally satisfying configuration or message for your audience?

Getting to an optimal set of features, benefits and claims as a core objective of your research is likely on your list, and in many circumstances, that consideration alone can be managed (without any of the other considerations above) with either IDIs or groups. It is typically not the main driver of choice for a qualitative format.

There are situations where it is very important to understand a minimum consensus claim set, or a minimum set of features or capabilities and benefits which will be agreeable to a significant majority of your audience.  This is valuable information to have in order to gain clarity concerning a new solution or in situations where the proposed concept perhaps doesn’t measure up in all areas in comparison with a competitive offering, for example. 

In these cases, groups are indispensable. Groups enable the moderator to actively engage a group of target audience members together and, through a discussion, agree to a minimally satisfying solution (if there is one to be found). This process is efficient and allows the moderator to test individual assertions against the rest of the group, and further probe on the reasoning behind each point or component. 

There are situations where IDIs are workable when consensus on minimally satisfying configurations are required (such as in situations where other more important drivers steer you away from groups), but it is more time intensive and is difficult to ascertain from initial IDIs in a series.

As with all marketing research, prior planning is paramount; plans for qualitative market research that include answers to these questions will result in much more usable results.



Both IDIs and focus groups have their utility in qualitative market research. When it’s time to decide which route to take, be sure you are asking the right questions of your marketing research partner and that they are providing the right justification for their response. Your reward will be the most effective research process and the most valuable information for making business decisions. 

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