Qualities of Good Questions
Good focus group questions have the following qualities.
Sound Conversational
The focus group is a social experience, and conversational questions help create and maintain an informal environment.
Use Words the Participants Would Use When Talking About the Issue
Don't use acronyms, jargon, and technical lingo unless you are talking to a group of experts. Professionals are sometimes held captive by their language and inadvertently use technical terms or jargon that sound highfalutin and confuse and put off lay audiences. To avoid this, have the questions reviewed by people similar to your target audience to make sure the language is clear and unpretentious.

Are Easy to Say
Good questions are written so the moderator won't stumble over words or phrases. Some questions are great in written form but are awkward or stilted when asked orally.
Are Clear
When the question is asked, participants should understand what you're asking. This sounds pretty basic, but it is surprising how confusing some questions are. Sometimes moderators give long preambles to questions, offer lengthy background, or use a long segue from one topic to another. Instead of clarifying the question, this can actually be confusing. Listeners may key on trivial phrases or words intended to build the case for the question, but these same phrases and words can confuse the focus group participant or take the discussion off on a tangent. Again, the question might be clear when one is reading it off the page but confusing when one hears it. When questions are unclear, either they don't make sense to the participant or they can be interpreted in different ways.
Are Usually Short
Lengthy questions can be confusing to respondents. Participants have a hard time distinguishing the core intent of the question. In general, you reduce clarity as the length of the question increases.
Are Usually Open-Ended
Open-ended questions are a hallmark of focus group interviewing. These questions imply that a few words or a phrase are insufficient as an answer. They beg for explanations, descriptions, or illustrations.
Although the moderator means well, the participants get confused. For example, "How was the program useful and practical to you?" For some, "useful" and "practical" may be very different concepts. Other times, moderators might add a second sentence or phrase that supposedly amplifies the question but confuses the respondents because it introduces another dimension. For example, "Which of these is most important to you? Or which should be acted on first?" Again, the moderator assumed that what was important should be acted on first, but this may not be the view of participants.
Include Clear, Well-Thought-Out Directions
When asking participants to do something, be sure to provide clear instructions. For example, if you are asking participants to list something, do you want them to write it down on paper before they discuss? How much time should they take? Practice the instructions whenever the tasks are complicated, such as when using small breakout groups or activities that have multiple steps.