Parents often try to determine what will be difficult, or what won't be, for their child. But sometimes parents and researchers get it wrong.

Depending on age and maturity, many children have a great ability to understand basic facts about a clinical study...and often want to have a say. Parents should always ask questions and get the details they need, but it is important to talk with your child and let him or her ask questions too.

But what do kids say about being in a study?

While parents and doctors may focus on drugs, or needles, or asking difficult questions, kids may be worried about staying overnight, how much school they will they miss or if there are other kinds of testing or physical exams. There may be things that scare your child about being in a study. Ask your child to talk with you about them and answer as honestly as you can. Across the board, children want very much to be able to ask their own questions...and feel at ease with the answers.

The point is, kids get it.

And because they do, it's important to listen to their concerns and questions...to give them a voice.

One thing researchers have found is that often times children in clinical studies were more willing and more interested in participating in future research to help other kids. They understand that it is a charitable activity.

Whatever their point of view is, find out. More than likely, they'll have a lot to say.