Editor's note: Monica Belmana is senior research manager, behavioral science, at research firm Material, Los Angeles. This is an edited version of a post published under the title, “Tips for conducting market research with kids.”

When you think of respondents, you probably imagine people taking online surveys and participating in focus groups. You probably also imagine those respondents being adults.

But for many brands, it’s the wants and needs of children that are driving their parents’ purchase decisions. A kid’s favorite TV show becomes their favorite backpack, lunch box and pair of pajamas. Their favorite color becomes their bedroom décor. Their favorite theme park becomes the family’s annual trip. The list goes on. Kids can be highly opinionated and selective consumers, and depending on your industry, it can be critical to understand their attitudes, habits and behaviors. And while you can always gather information through a proxy, such as a child’s caregiver, hearing directly from the child is much more impactful.

But children are not just tiny adults. They operate differently, which can make researching them tricky. Depending on their age, they don’t quite understand the question-and-answer process the way adults do. They are, depending on their age, both more candid and more easily influenced by their peers, parents or an in-person interviewer. They are also continuously growing, learning and developing new skills, which means they quickly age out of (and into) products and media.

It’s also worth noting that, before the age of four, we don’t recommend interviewing children because their language and thought processes are still extremely limited. Instead, an observational approach is more effective. Parental consent is required before collecting a child’s personal information for all children 12 years old and younger in the United States; other jurisdictions have similar restric...