As students develop and learn, their conceptual understandings change over time. Even when presented with new information, students may continue to believe their own understanding. In addition, the developmental level of children that allows them to make connections changes as they grow. Younger children may not be able to conceptualize certain concepts that are above their level.

Blood is a key element in the human body and moves throughout it continuously. We were interested in the understanding of both children and adults of what blood does for the body as well as how it moves within the body. This includes the interactions between blood, the heart, and other vesicles through which blood travels. We asked a variety of children ranging from ages 3-12 the following research questions to see what their understanding of blood is. Their interviews included both oral and written activities.